Unit 4 Test Review

Question 1

What are 3 ways to separate mixtures?

Answer 1

fliteration, distelation, magnet

Question 2

Can elements be separated?

Answer 2

No

Question 3

Can a compound be separated?

Answer 3

Yes

Question 4

What is a compound?

Answer 4

2 or more elements put together

Question 5

List the 7 diatomic elements

Answer 5

Cl, I, F2, H2, Br2, O2, N2

Question 6

what does it mean that these elements are diatomic?

Answer 6

they are elements made of 2 or more atoms

Question 7

state Avogadro’s Hypothesis

Answer 7

2 equal volumes of gas, at the same temp and pressure, contain the same number of molecules

Question 8

Describe an atom in your own words

Answer 8

The basic unit of a chemical element. (check with Quick for this one.)

Question 9

explain how the law of multiple proportions supports an atomic model of atoms?

Answer 9

w

Question 10

what is the law of definite proportions?

Answer 10

Elements always react in defined proportions and compounds are always composed of the same elements.

Question 11

how does the law of definite proportions support an atomic model of atoms?

Answer 11

w

Question 12

What is Dalton’s Atomic Theory?

Answer 12

1) All matter is made of atoms. Atoms are indivisible and indestructible. 2) All atoms of a given element are identical in mass and properties. 3) Compounds are formed by a combination of two or more different kinds of atoms.

Question 13

What is a pure substance?

Answer 13

a pure substance is only one molecule/particle. All are the same and can only be separated by chemical means.

Question 14

What is a mixture?

Answer 14

Consists of many different molecules/ particles. Can be separated by physical means.

Question 15

What does heterogeneous mean?

Answer 15

May exist in one phase an have variable properties in different parts of the sample.

Question 16

What does homogeneous mean?

Answer 16

Exists in one phase only and has uniform properties throughout the sample.

Question 17

What does it mean when atoms are diatomic?

Answer 17

The are elements made of 2 or more atoms.

Question 18

What is the law of multiple proportions?

Answer 18

Wherever two elements form more than one compound, the different masses of one element that combine with the same mass of the other element are in the ratio of small whole numbers

Question 19

What are gasses?

Answer 19

Particles are independent, widely separated, with no attractive forces between them. They fill the volume of the container.

Question 20

What is a liquid?

Answer 20

Particles constantly make and break temporary attractions between each other. Particles can slip past one another easily. They take the shape of the container.

Question 21

What is a solid?

Answer 21

Strong attractions between particles lock them into a fixed arrangement.

Question 22

What is a pure substance?

Answer 22

These have fixed compositions, one set of intrinsic physical properties (density, mp, and bp) and can be separated only by chemical means.

Question 23

what is a mixture?

Answer 23

These have variable composition. Their physical properties vary depending on the composition. They can be separated by physical means.

Question 24

what is an element?

Answer 24

These cannot be broken down into simpler substances by physical or chemical means. The smallest particle of this is called an atom.

Question 25

what is a compound?

Answer 25

These are made of elements in fixed mass ratios. They can be broken down into simpler substances by chemical means.

Question 26

Can heterogeneous and homogeneous mixtures be separated?

Answer 26

Yes because it is a mixture.