Chemists can identify the composition of some unknown salts by conducting a flame test. When potassium salts are heated in a flame, a purple color is observed.
This is due to the movement of electrons between energy levels. What is the electron configuration of a potassium atom at ground state?
answer choices
1s2; 2s2; 2p6; 3s2; 3p6; 4d1
1s2; 2s2; 2p6; 3s2;3p6; 3d1
1s2; 2s2; 2d6; 3s2; 3d6; 4s1
1s2; 2s2; 2p6; 3s2; 3p6; 4s1

Significant figures are important in scientific measurements because they indicate the precision and accuracy of the measurement, and ensure that calculations and conclusions based on those measurements are valid and reliable.

Significant figures are important in scientific measurements because they indicate the precision or accuracy of a measurement. The number of significant figures in a measurement represents the number of digits that are known with certainty plus one estimated digit.

It is important to use the correct number of significant figures when reporting measurements to ensure that the data is reliable and consistent. Using too few or too many significant figures can lead to incorrect calculations or conclusions. Therefore, scientists must be careful to use the appropriate number of significant figures when measuring and reporting data.

To know more about measurements, here

brainly.com/question/11407134

#SPJ4

--The complete question is, What is the importance of significant figures in scientific measurements?--

The molar mass of the gas, given that 3.25 g of the gas occupied 2.56 L is 30.66g/mol

To obtain the molar mass of the gas, we shall first obtain the number of mole of the gas. This can be obtained as follow:

PV = nRT

0.95 × 2.56 = n × 0.0821 × 280

Divide both sides by (0.0821 × 280)

n = (0.95 × 2.56) / (0.0821 × 280)

n = 0.106 mole

Haven obtain the mole of the gas, we shall determine the molar mass of the gas as follow:

Molar mass = mass / mole

Molar mass of gas = 3.25 / 0.106

Molar mass of gas = 30.66g/mol

Thus, the molar mass of the gas is 30.66g/mol

Learn more about molar mass:

https://brainly.com/question/15874532

#SPJ1

Answer:

The noble gases are the chemical elements in group 18 of the periodic table. They are the most stable due to having the maximum number of valence electrons their outer shell can hold. Therefore they rarely react with other elements since they are already stable

Answer:

Accuracy

I guess

Cause then it makes sense

Hope this helps

Change in temperature of the metal, ΔT₁ = 82.9°C

Change in temperature of water, ΔT₂ = 4.7°C

Temperature is a measure of the average kinetic energy of the molecules in a substance.

It is defined as the degree of hotness or coldness of a body.

Temperature changes occur when heat is added or removed from a substance.

To determine the temperature change in water and the meatal when the heated aluminum was placed in water, the following calculations are done:

Initial temperature of metal = 100°C

Initial temperature of water = 22.4°C

Final temperature of both = 27.1°C

Change in temperature of the metal, ΔT₁ = 100 - 27.1

ΔT₁ = 82.9°C

Change in temperature of water, ΔT₂ = 27.1 - 22.4°C

ΔT₂ = 4.7°C

In conclusion, the change in temperature is determined by finding the difference in the temperatures.

Learn more about temperature change at: https://brainly.com/question/24719561

#PSJ1

Answer:

100

22.4

27.1

4.7

72.9

Explanation:

It just is, trust me

The ammonium nitrate concentration in the resulting solution is 0.08 M.

The molarity and volume are related to each other by the formula -

\( M_{1}\) \( V_{1}\) = \( M_{2}\) \( V_{2}\), where values at Left Hand Side are initial concentration and volume and values are Right Hand Side are final concentration.

Keep the values in formula to find final concentration.

0.467 × 50 = \( M_{2}\) × 290

Performing multiplication in the equation

\( M_{2}\) = 23.35 ÷ 290

Performing division on Right and Side of the equation

\( M_{2}\) = 0.08 M

Thus, the final molarity is 0.08 M.

Learn more about concentration -

https://brainly.com/question/26255204

#SPJ4

Answer:

11.9 g of nitrogen monoxide

Explanation:

We'll begin by calculating the number of mole in 6.75 g of NH₃. This can be obtained as follow:

Mass of NH₃ = 6.75 g

Molar mass of NH₃ = 14 + (3×1)

= 14 + 3

= 17 g/mol

Mole of NH₃ =?

Mole = mass /molar mass

Mole of NH₃ = 6.75 / 17

Mole of NH₃ = 0.397 mole

Next, we shall determine the number of mole of NO produced by the reaction of 0.397 mole of NH₃. This can be obtained as follow:

4NH₃ + 5O₂ —> 4NO + 6H₂O

From the balanced equation above,

4 moles of NH₃ reacted to produce 4 moles of NO.

Therefore, 0.397 mole of NH₃ will also react to produce 0.397 mole of NO.

Finally, we shall determine the mass of 0.397 mole of NO. This can be obtained as follow:

Mole of NO = 0.397 mole

Molar mass of NO = 14 + 16 = 30 g/mol

Mass of NO =?

Mass = mole × molar mass

Mass of NO = 0.397 × 30

Mass of NO = 11.9 g

Thus, the mass of NO produced is 11.9 g

-2269.2kJ is the enthalpy change of a given equation for 4 moles  . the negative value indicates that the given reactions are spontaneous reactions .

These equations and enthalpy of reaction is  given by Hess’s law, the chemical equation can be treated as algebraic expressions . That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.

P4(s) + 10 Cl2(g)--> 4 PCl5(s) ΔH°rxn= -1774.0 kJ

PCl3(l) + Cl2(g)--> PCl5(s) ΔH°rxn = -123.8 kJ  (  Multiply  by 4 )

then the value of enthalpy change  for equation 2 be  -495.2kJ

then according to enthalpy change equation

delta H = delta h1 - delta h2

delta H = -1774.0 -(- 495.2)

delta H = - 2269.2KJ

for 4 moles  the value of enthalpy change is -2269.2kJ

the value of enthalpy change for 1 mole is  - 567.3 KJ

To know more about Hess’s law, click here:

https://brainly.com/question/14561923

#SPJ4

Answer:

Opposite poles of attract each other and make bonds.

Explanation:

Those compounds are soluble in water which have polar nature means that make poles with other atoms while on the other hand, those compounds which doesn't have polar nature are dissolve in non-polar solvent. The polar nature of compounds is due to their difference in electronegativities so in polar compounds opposite poles attract one another and make bonding with each other.

The attractive forces between ions in a polar compound that is very soluble in water compared to a relative less polar compounds that is relatively insoluble in water.

Those molecules in which within a molecule two opposite poles of opposite charges are present.

If we want to dissolve any molecule in the water then that molecule should posses a negative end which get attracted towards the H⁺ ion of the water, and also posses a positive end which get attracted towards the OH⁻ ion of water to get dissolve.

So, those molecules which are non polar are insoluble in water.

To know more about polar molecules, visit the below link:
https://brainly.com/question/8855423

As the first blank is already filled, this first property is called the Cohesive property of water, which is what makes it possible to clump together into drops, due to their intermolecular forces.

The second blank is talking about density, and as we can see in our daily lives, ice is less dense than water, therefore in this blank liquid water will be MORE dense than ice, this is due to the hydrogen bonds and the orientation in which they are causing the molecules to push farther apart.

As we have discussed in the second blank, this 3rd blank is ICE FLOATS

Answer:

(o) Al + NaOH + H2O -NaAlO2 + H2.

When aluminum oxide Al 2 O 3 reacts with sodium hydroxide solution, it forms sodium aluminate and water H 2 O . This reaction takes place at a temperature of 900 - 1100 ° C

Coleoptile 1: Plant with a white agar cube lacking chemical.

Chemistry is indeed the scientific investigation of material, including its composition, behavior, structure, and qualities. It is the branch of science that deals with the study of the structure and composition of matter, including its physical and chemical properties, and its reactions to other substances. Chemistry is a vast field that encompasses many different topics, such as atomic structure, chemical bonding, chemical reactions, organic chemistry, inorganic chemistry, biochemistry, and analytical chemistry. Chemistry is an essential part of everyday life and has applications in many areas, such as health, agriculture, industry, and the environment.
This coleoptile will not bend at all, since the agar cube is not emitting any chemical signals.

Coleoptile 2: Plant with a pink agar cube with chemical. This coleoptile will bend to the right, since the agar cube is emitting growth-promoting chemical signals, and is placed off-center with the yellow arrows indicating directional light.

To learn more about  chemical
https://brainly.com/question/1222323
#SPJ1

1.945 x 10²⁴ molecules make up 3.23 moles.

In the case of sodium chloride, Sodium chloride, there are Avogadro's number of formula units for each mole of Sodium chloride (molecules). So, the number of Sodium chloride formula units (molecules) we need to determine is equal to the number of movements times all of the data we have is constant.

To convert from moles to molecules, you need to use Avogadro's number, which is 6.022 x 10²³ molecules per mole.

So, to convert 3.23 mol to molecules:

3.23 mol x 6.022 x 10²³ molecules/mol = 1.945 x 10²⁴ molecules.

To know more about molecules visit:-

https://brainly.com/question/15123235

#SPJ1

Chromium is the metal impurity that makes rubies red and emeralds green.


Impurities are the foreign substances that enter into the crystal lattice of the mineral or gemstone. The addition of impurities causes the gemstone to change its color. In the case of rubies and emeralds, the presence of a particular metal impurity is responsible for the red and green color of the gemstones, respectively.

Chromium is the metal impurity that causes the ruby to appear red. It enters into the lattice of aluminum oxide (Al2O3), which is the main constituent of rubies. The amount of chromium present in the crystal lattice determines the color of the ruby. The more the amount of chromium present in the crystal lattice, the deeper the color of the ruby.

In the case of emeralds, the metal impurity that causes the green color is chromium and vanadium. The addition of chromium and vanadium to the crystal lattice of beryl (Be3Al2(SiO3)6) gives it a green color. The color of the emerald depends on the amount of chromium and vanadium present in the crystal lattice.

Learn more about crystal lattice here:

https://brainly.com/question/8459142

#SPJ11

Due to the nucleus' extreme hardness and density, which prevents alpha particles from passing through, only a very small number of alpha particles actually recovered when they hit the gold foil, as observed by Rutherford.

The composite alpha particle consists of protons and neutrons that are firmly linked together. They are released from some radionuclides' nuclei through an event known as alpha-decay, a kind of radioactive decay.

The alpha particle has a mass of four units and a positive charge of two units. Consequently, it contains the helium atom's nucleus.

Every atom's nucleus has a neutron, with the exception of plain hydrogen, which does not. The name of the particle derives from the fact .

To know more about Alpha particles visit :

https://brainly.com/question/2288334

#SPJ4

Answer: True

Air is a mixture of many things; it's not just Oxygen, but Hydrogen, Carbon, and Nitrogen as well are made up of air. Fun fact: Nitrogen is actually more abundant in air

To calculate the heat released during the combustion of methanol, you will need to know the heat of combustion of methanol, which is the amount of heat released when a given amount of methanol is burned in oxygen.

The heat of combustion of methanol is -726 kJ/mol.

To find the heat released in kJ using 790 grams of water and a temperature change of 9.1 degrees Celsius,

you will need to use the formula q = m * c * deltaT, where q is the heat released, m is the mass of the substance being heated (in this case, water), c is the specific heat of the substance, and deltaT is the change in temperature.

In this case, the heat released would be:

q = 790 g * 4.18 J/(g*C) * 9.1 C = 28,903.22 J.

To convert this to kJ, you would divide by 1000 to get 28.90322 kJ. Rounded to the nearest integer, the heat released would be 29 kJ.

Learn more about combustion of methanol:
https://brainly.com/question/12655480

#SPJ4

The specific gravity of urine is a measure of the concentration of dissolved particles in the urine. These particles include salts, minerals, and waste products, among others. The specific gravity of urine varies depending on factors such as fluid intake, diet, and health status.

When fluid intake is normal, the specific gravity of urine should be between 1.010 and 1.025. This range reflects a healthy balance of hydration and waste elimination. If the specific gravity is lower than 1.010, it may indicate that the person is overhydrated or has a condition that affects the kidneys' ability to concentrate urine. On the other hand, if the specific gravity is higher than 1.025, it may indicate dehydration, a high-protein diet, or a condition that affects the kidneys' ability to dilute urine.

It is important to note that specific gravity measurements are not definitive and should be interpreted in conjunction with other clinical data. For example, if a person has a high specific gravity but no symptoms of dehydration, further tests may be needed to determine the cause. Similarly, a person with a low specific gravity may need additional tests to rule out kidney disease or other conditions.

In conclusion, when fluid intake is normal, the specific gravity of urine should be between 1.010 and 1.025. However, specific gravity measurements should be interpreted in the context of other clinical data to accurately assess a person's health status.

Learn more about hydration here:

https://brainly.com/question/11202174

#SPJ11

When the umbilical cord is tied after birth, the umbilical arteries close by filling in with connective tissue. The umbilical arteries carry deoxygenated blood from the fetus to the placenta, where the blood is oxygenated and returned to the fetus via the umbilical vein.

When the umbilical cord is cut, the flow of blood from the placenta to the fetus ceases, and the umbilical arteries and vein begin to constrict. This constriction is caused by the contraction of smooth muscles in the vessel walls and the closure of small valves within the vessels. As the umbilical arteries constrict, the flow of blood to the placenta decreases and the vessels begin to fill in with connective tissue. Over time, the connective tissue replaces the smooth muscle and valve tissue in the vessel walls, resulting in the complete closure of the umbilical arteries. This process is important to prevent bleeding and infection in the newborn.

Learn more about placenta here:

https://brainly.com/question/26959441

#SPJ11

A primary explosive is a sensitive explosive that almost always explodes with a single ignition from a primary heat source of sufficient intensity, such as a spark, flame, impact, or other primary heat source.

Primary explosives can explode as a result of a spark or a relatively weak mechanical stress. They start the primary explosive when used as blasting caps (detonators). Additionally, they are loaded with friction-mixed materials and other ingredients in percussion caps.

A highly brisant starting explosive with a high triggering velocity is required. Mercury fulminate, lead azide, lead trinitroresorcinate, silver azide, diazodinitrophenol, and tetrazene, which is a primer additive, are the most significant primary explosives.

Only if they have already been pressed into capsules must initiation charges be transported.

Therefore, A primary explosive is a sensitive explosive that almost always explodes with a single ignition from a primary heat source of sufficient intensity, such as a spark, flame, impact, or other primary heat source.

To learn more about lead azide, refer to the link:

https://brainly.com/question/21506930

#SPJ1

The first rule for predicting the products of a chemical reaction is to identify the type of reaction that is taking place.

Chemical reactions can be broadly classified into five types: Combination or synthesis reaction: A combination reaction occurs when two or more reactants combine to form a single product. The general form of the combination reaction is A + B → AB.

Decomposition reaction: A decomposition reaction occurs when a single reactant breaks down into two or more products. The general form of the decomposition reaction is AB → A + B.

Single displacement or substitution reaction: A single displacement reaction occurs when an element displaces another element in a compound, and takes its place. The general form of a single displacement reaction is A + BC → AC + B.

Double displacement or metathesis reaction: A double displacement reaction occurs when two compounds exchange ions, and form two new compounds. The general form of a double displacement reaction is AB + CD → AD + CB.

Combustion reaction: A combustion reaction occurs when a substance reacts with oxygen, and produces heat and light. The general form of a combustion reaction is CxHyOz + O₂ → CO₂ + H₂O.

To know more about chemical reaction here

https://brainly.com/question/29762834

#SPJ4

Answer: here, for those of you who can't see it upright

Explanation:

Each element have its own electronic configuration.The first given configuration is with 4 electrons represents beryllium (Be) and the second one with 9 electrons is Fluorine (F) and the last one with 11 electrons is sodium (Na).

An orbital is a circular path with fixed energy through which electrons in an atom revolving around the nucleus. Electrons are filled in these orbitals based on the energy levels.

Lowest energy orbitals are filled first and the higher energy orbitals are filled last. Each orbital has a specific capacity to accommodate electrons. S orbital fill only two electrons, p orbital fill 6 electrons d orbital 10 electrons and f orbital fills 14 electrons.

The first electronic configuration have a total 4 electrons thus the element with atomic number 4 is Beryllium (Be) and the second configuration have 9 electrons thus it is Fluorine (F).

The last configuration represented as slashes have a total of 11 electrons. The element with 11 electrons is sodium (Na).

To find more about orbitals, refer the link below:

https://brainly.com/question/18914648

#SPJ2

Answer:

Explanation:

the addition of an indicator to the analyte solution helps us to visually spot the equivalence point in an acid-base titration. Endpoint: refers to the point at which the indicator changes color in an acid-base titration.

Answer:

Calculate the volume (in L) occupied by 3.40 g of NH3 at STP. (STP: 0 degree Celsius and 1 atmosphere of pressure).

Explanation:

To get the volume of ammonia gas at STP, calculate the number of moles of \(NH_3\) in the given amount.

Number of moles of \(NH_3\) gas is:

\(number of moles of NH_3 gas&=\frac{given mass of the gas}{its molecular mass} \\ &=\frac{3.40g}{17.0g/mol} \\&=0.2 mol.\)

Since,

1 mol of any gas at STP occupies ------- 22.4 L of volume.

then,

0.2 mol of \(NH_3\) occupies how much volume?

\(=>0.2 mol x \frac{22.4 L}{ 1.0 mol} \\=4.48 L\)

Hence, the volume occupied by 3.40 g of ammonia at STP is --- 4.48 L.

Taking into account the Newton's second law, the correct answer is the last option: the force needed is 270 N.

In first place, acceleration in a body occurs when a force acts on a body, and two factors influence the acceleration of an object: the net force acting on it and the mass of the body.

Newton's second law states defines the relationship between force and acceleration mathematically.

This law says that the acceleration of an object is directly proportional to the sum of all the forces acting on it and inversely proportional to the mass of the object.

Mathematically, Newton's second law is expressed as:
F= m×a

where:

In this case, you know:

Replacing in the Newton's second law:

F= 54 kg× 5 m/s²

Solving:

F= 270 N

Finally, the correct answer is the last option: the force needed is 270 N.

Learn more about the Newton's second law:

brainly.com/question/23845187?referrer=searchResults

brainly.com/question/13959891?referrer=searchResults

One benefit of someone using nuclear energy is that it operates with more reliability. Is Because they require minimal maintenance, nuclear power facilities are built to run continuously.

Fission, the breaking of uranium, is the source of nuclear energy. As a result, heat is produced, which then turns water into steam and powers a turbine generator. Since nuclear power plants don't burn fuel, they don't produce greenhouse emissions.

Nuclear energy seems to be the term used to describe the force contained in the center, or core, of an atom. Nuclear energy may be used to generate electricity, but it must first be liberated from the atom.

To know more nuclear energy visit:

https://brainly.com/question/27033205

#SPJ4

Answer:

Yes I'll help you

Tactics are similar to those of ecoterrorists. This best describes the campaign. Therefore, the correct option is option B.

Natural Resources Defence Council, and others once engaged in a campaign against Kimberly-Clark known as campaigns. From 2004 to 2009, it took place. The largest producer of tissue products in the world, Kimberly-Clark is well known for its Kleenex brand.

Every year, the company buys from logging companies more than three million kilogrammes (3.4 million tonnes) of fibre. According to the marketing campaign, this fibre is made with old growth forest wood pulp. Tactics are similar to those of eco. This best describes the Kleercut campaign.

Therefore, the correct option is option B.

To know more about campaign, here:

https://brainly.com/question/30293626

#SPJ1

An exothermic process called combustion necessitates the interaction of fuel with a reducing agent.

An object quickly reacts with oxygen in the chemical process of burning to produce heat. Fuel and oxygen's source are the terms used to describe the original substance. Although fuel for aeroplane propulsion is normally a liquid, it can also be a solid, liquid, or gas.

Learn more about Combustion here:

https://brainly.com/question/25141046

#SPJ4