A compound contains 42.1% sodium, 18.9% phosphorus and 39% oxygen.

Determine its empirical formula(show all your work).

Answer:

4.5

Explanation:

2KClO3 ===> 2KCl + 302

Let the number of moles of KClO3 = x

2KClO3 ===> 2KCl + 302

Since the balance numbers are the same for both chemicals KClO3 and KCl whatever you need to get for KCl will be the same as for the KCl

x = 4.5

Answer:

The oeriodic table have 8 groups

Answer:

as temperature increases it speeds up chemical reactions and that accelerates the spoiling process of food. Keeping food in a cold place (a fridge) slows down those processes.

This is a type of bond present in electrovalent compounds.

This is a type of bond that exist in electrovalent or ionic compounds. It is formed as a result of combination between a positive cation and a negative anion. This results in the transfer of electron from the cation to the anion. This type of bond in which there's a complete transfer of electrons between both parties occurs easily as a result of the electronegative difference between the combining atoms. Compounds that show this type of bonding are combination between group 1 or 2 elements with group 16 or 17 elements.

Compound formed through this bond are strong, mostly dissolves in polar solvents due to their polar charges and also conducts electricity.

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Answer:

convergent boundary subduction zone

Explanation:

Answer:

The motion of the plates would be considered a convergent boundary which is where old crust goes under the new crust and is reheated overtime. This could also be known as a convection current. This is when the mantle is heated up and rises to the top an when it cools off, it goes back down and then that cycle repeats itself overtime.

Explanation:

Plato

Answer:

The molar mass is 138.8843 g/mol 

Answer:

The answer is chemical weathering due to water reacting with calcite

Explanation:

The causes of chemical weathering include the action of water, oxyen, carbon dioxide, living organisms, and acid rain.

Answer:

When iron wool combusts, it reacts with oxygen from the air to form iron oxide. Iron oxide is a solid, so the oxygen atoms from the air add to the mass on the balance. The balance tips as the iron wool reacts with the oxygen to form solid iron oxide. from.

Explanation:

Answer:

D) I think is single displacement (replacement)

Answer a) 12 neutrons
b) 12 electrons
a) 12 protons

Explanation:

The atomic number is the number of protons in an atom and is also the number of electrons
therefore, the number of protons and electrons = 12

the mass number of an element is = # of protons + # of neutrons
if we rearrange it to find # of neutrons,
# of neutrons = mass number - # of protons
so, 24 - 12 = 12 neutrons

Answer:

you can do it

Explanation:

Answer:

Strontium

Explanation:

To find the element, we need to know the atomic number. There is this rule in chemistry that says that the number of protons and the atomic number are the same. Since we know that there are 38 protons, the atomic number is also 38, leading us to Strontium. Sr -- element symbol.

The mass number is located below the element symbol on a periodic table. The mass number or the atomic mass for Strontium is 87.62 u.

Since there are an uneven amount of protons and electrons, let's subtract the number of electrons from the number of protons to find the difference. 38-36 = 2. (Also, protons are positive and electrons are negative, meaning there are more + than - in the ionic charge). Which means, the atom has a +2 ionic charge.

1) list givens and convert if necessary

C₁ = 3.50 mol/L

V₁ = 0.550 L

C₂ = ?

V₂ = 0.275 L

2) rearrange formula

[tex]C_{1}V_{1}=C_{2}V_{2}\\\\C_{2}=\frac{C_{1}V_{1}}{V_{2}}[/tex]

3) solve

[tex]C_{2}=\frac{(3.50\ mol/L)(0.550\ L)}{(0.275\ L)}[/tex]

C₂ = 7.00 mol/L

Answer:

             Point - C

Explanation:

Ethylamine has a molar mass = 45.08 g/mol

While, HBr has molar mass = 80.91 g/mol

This means ethylamine will travel more distance than HBr in given time.

So, the white solid (Ethylammonium bromide) will form at point C.

Why Point C?

Point C is the only point which is farthest from ethylamine and closest to HBr. This point depicts that ethylamine has travelled more distance than HBr.

Key words:-

Now

Apply combined gas law

[tex]\\ \tt\hookrightarrow \dfrac{P_1V_1}{T_1}=\dfrac{P_2V_2}{T_2}[/tex]

[tex]\\ \tt\hookrightarrow \dfrac{1(1.2)}{273}=\dfrac{(0.800)V_2}{299}[/tex]

[tex]\\ \tt\hookrightarrow 0.004=0.002V_2[/tex]

[tex]\\ \tt\hookrightarrow V_2=2L[/tex](Approx)

Answer:

11318 feet and 10.771 inches

Explanation:

there is 3280.84 in one Km

just do 3280.84x3.45

Answer:

alll of them are possible, besides the last one

Explanation:

All of them are correct compounds besides the last one. The last one isn’t a correct compound because the second element does not exist

#NaO_2

Correct compound=Na_2O

#MgCl_2

#CaF

#NaBr

#KHe

Helium is a noble gas so can't form compounds

Answer:

Option B is correct.

Explanation:

Distance refers to the distance traveled by a body.

Hope it will help you.

Muscular and nervous system involved

Based on the observations, the change is physical.

This is because the matter is still the same composition after the change, while a chemical change would change the composition.

Based on the observations, both physical and chemical changes have occurred during the experiment.

Observation 1: Water droplets form on the inside of the glass lid. This is a physical change.

Observation 2: Bubbles rise as the water starts boiling. This is a chemical change.

A physical change is a transformation in a substance's state, shape, or form that does not alter its chemical composition or create new substances. During a physical change, the original substance remains the same, and no chemical bonds are broken or formed.

A chemical change, also known as a chemical reaction, involves the conversion of one or more substances into new substances with different chemical compositions. Evidence of a chemical change includes the production of gas, formation of a precipitate, release or absorption of heat or light, and changes in color and odor.

In observation 1, the water vapor in the air comes into contact with the cooler glass surface of the lid and condenses back into liquid water. Condensation is a physical change where a gas changes into a liquid.

Observation 2- Boiling is the process of converting liquid water into water vapor (gas) by absorbing heat energy. The heat causes water molecules to gain energy and transform into gas, forming bubbles that rise to the surface. This change involves the breaking of intermolecular forces between water molecules and is a chemical change.

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#SPJ3

Answer:

All life on Earth descended from a common ancestor

The Volume and the density of the box are 480 in³, 7865.81 cm³, 0.127 g/mL

This is the measure of the capacity of substance an object can hold.

To calculate the volume  of the box, we use the formula below

Formula:

Where:

From the question,

Given:

Substitute these values into equation 1

We convert the volume from cubic inches to cubic centimeters using the expression below.

Density can be defined as the ratio of the mass and volume of a body.

To calculate the density of the box, we use the formula below.

From the question,

Given:

Substitute these values into equation 2

Hence, The Volume and the density of the box are 480 in³, 7865.81 cm³, 0.127 g/mL.

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Answer:

"At the top of the first and tallest hill, your potential energy is at its highest it will ever be on this ride. As you begin to descend, your potential energy decreases until it's all gone at the bottom of the hill." The shorter the hill the roller coaster climbs, the greater its kinetic energy.

Answer:

b) 3.000 mol S

Explanation:

using Avogadro's constant

1 mol = 6.02 × 10^23 atoms

we need to find the number of moles for 1.806 × 10^24

x = 1.806 × 10^24

putting it together we now have:

1 mol = 6.02 × 10^23 atoms

x = 1.806 × 10^24

cross multiply

6.02 × 10^23 x = 1.806 × 10^24

divide both sides by 6.02 × 10^23

x = (1.806 × 10^24) ÷ (6.02 × 10^23) = 3 mol

Answer:

41. False

42. True

43. False

44. False

45. True

46 - 48. Unsure (I don't take Biology, sorry.)

Explanation:

41.

FeS and HCl are the reactants of the chemical equation. Hence, false.

42.

It is common knowledge that HCl and H₂SO₄ are acids. Hence, true.

43.

Vinegar contains acetic acid CH₃COOH, which isn't a base. Hence, false.

44.

Fluorescence is actually the emittance of light by any substance due to radiation. Hence, false.

45.

Yes, the image produced by a plane mirror is laterally inverted. Hence, true.

Answer:

If they all had the same eye color it would probably be hazel, but If they did not then it would either be blue or brown.

Explanation:

Hope this helps

Option C is the right answer

The medium through which the velocity of a sound wave is greatest is: C. steel.

A sound wave can be defined as a form of mechanical wave that requires a medium for its propagation and it creates a disturbance in the medium. Thus, a sound wave needs a medium to travel and it creates a disturbance when it travels through any medium.

Some examples of the parameters of a sound wave include the following:

Generally, the velocity of a sound wave is greatest in a solid medium such as steel than in liquid or gaseous medium.

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