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3 years ago

If a substance cannot be broken down chemically into a simpler substance what is it

Chemistry

2 answers:

Vikentia [17]3 years ago

6 0

Answer: An Element

Explanation:

An element is a substance that cannot be split into smaller substance. It is made up of one kind of atom and can exist either as molecules (e.g nitogen) or an atom (e.g argon).

stellarik [79]3 years ago

3 0

Answer: an element

Explanation:

Elements are only composed of one type of atom

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What relationship does Avogadro's law describe?

LenaWriter [7]

Answer:

D. The relationship between volume and moles

Explanation:

Amedo Avogadro found the relationship between the volume of a gas and the number of molecules contained in the volume.

The law states that "equal volume of all gases at the same temperature and pressure contains the same number of molecules or moles".

Mathematically:

V ∝ n (P,T constant)

4 0

3 years ago

Calculate the amount of oxygen gas collected by the displacement of water at 14◦C if the atmospheric pressure is 790 Torr and th

zhannawk [14.2K]

Answer : The amount of oxygen gas collected are, 0.217 mol

Explanation :

Using ideal gas equation :

$PV=nRT$

where,

P = pressure of gas = $(790-12)torr=778torr=1.02atm$ (1 atm = 760 torr)

V = volume of gas = 5 L

T = temperature of gas = $14^oC=273+14=287K$

n = number of moles of gas = ?

R = gas constant = 0.0821 L.atm/mol.K

Now put all the given values in the ideal gas equation, we get:

$(1.02atm)\times (5L)=n\times (0.0821L.atm/mol.K)\times (287K)$

$n=0.217mole$

Thus, the amount of oxygen gas collected are, 0.217 mol

8 0

3 years ago

Identify the change in state that does NOT have an increase in entropy. Identify the change in state that does NOT have an incre

Lena [83]

Answer:

condensing water

Explanation:

Entropy refers to the level of disorderliness in a system. The entropy of liquids is greater than that of solids. The entropy of gases is greater than that of liquids.

A process of physical change involving a change of state from solid to liquid or liquid to gas is accompanied by increase in entropy.

However, a change of state involving a change from liquid to solid or gas to liquid is accompanied by decrease in entropy.

Hence, steam condensing to water leads to decrease and not increase in entropy of the system.

4 0

3 years ago

How is Earth's surface most likely To

AleksAgata [21]

Answer:

A. Cracks in rocks will deepen as the roots grow.

3 0

2 years ago

Read 2 more answers

A radioactive nucleus alpha decays to yield a sodium-24 nucleus in 14.8 hours. What was the identity of the original nucleus?

Rudik [331]

Answer:

2813Al

Explanation:

You know that alpha decay takes place when a α-particle is being ejected from the nucleus of a radioactive isotope.An

α-particle is simply the nucleus of a helium-4 atom. A helium-4 atom has a total of two protons and two neutrons in its nucleus, and two electrons surrounding that nucleus.

In that case, if a α-particle is the nucleus of a helium-4 atom, then it must have a mass number equal to 4, since it has two protons and two neutrons, and a net charge of (2+) since it no longer has the two electrons that the helium-4 atom has.

So, you know that an unknown radioactive isotope decays via alpha decay to yield a sodium-24 nucleus.

A sodium-24 nucleus contains 11 protons and 13 neutrons. This means that you can write

AZX→2411Na+42α

Here A and Z represent the unknown element's mass number and atomic number, respectively.

So, if you take into account the fact that mass number and atomic number must be conserved in a nuclear reaction, you can say that

A=24+4 and Z=11+2

The unknown isotope will thus have

{A=28Z=13

A quick look at the periodic table will show you that the element that has 13 protons in its nucleus is aluminum, Al. This means that you're dealing with aluminum-28, an isotope of aluminum that has 15 neutrons in its nucleus.

The complete nuclear equation will be

2813Al→2411Na+42α

5 0

3 years ago