Term 4 Science Content (Chemistry)

Question 1

Physical change

Answer 1

• Involves only a change to the physical property of a substance such as its shape, state or temperature
• A physical change can usually be reversed as no new substance is formed
• For example, when water freezes to ice its properties change. It is now a solid - but it is still water. And it can be easily changed back to liquid water

Question 2

Chemical change

Answer 2

With a chemical change, one or more new substances are formed.

Question 3

Two types of change

Answer 3

• Chemical Change
• Physical Change

Question 4

Chemical compounds

Answer 4

Consist of atoms of two or more elements joined together in certain fixed combinations

Question 5

How many hydrogen atoms are there in each molecule of ammonia, NH3?

Answer 5

3

Question 6

T/F: An atom can be divided

Answer 6

True

Question 7

What can atoms be broken down into?

Answer 7

Sub-atomic particles

Question 8

The number of types of sub-atomic particles

Answer 8

3

Question 9

The types of sub-atomic particles

Answer 9

• Proton
• Neutron
• Electron

Question 10

Electrical charge of a proton

Answer 10

Positive

Question 11

Electrical charge of a neutron

Answer 11

Neutral

Question 12

Electrical charge of a electron

Answer 12

Negative

Question 13

Mass of a neutron compared to one proton

Answer 13

1

Question 14

Mass of an electron compared to one proton

Answer 14

1/1840

Question 15

Position of protons in an atom

Answer 15

Inside the nucleus

Question 16

Position of neutrons in an atom

Answer 16

Inside the nucleus

Question 17

Position of electrons in an atom

Answer 17

Outside the nucleus

Question 18

Which subatomic particle is not found in the nucleus?

Answer 18

Electron

Question 19

Which subatomic particle has no electrical charge?

Answer 19

Neutron

Question 20

The mass of the neutron is approximately equal to the mass of the:

Answer 20

Proton

Question 21

Most of an atom’s volume is made up of:

Answer 21

Empty space

Question 22

Where is most of the mass of an atom located?

Answer 22

Inside the nucleus

Question 23

Overall, the nucleus has a ____________ electrical charge.

Answer 23

Positive

Question 24

Chemical element

Answer 24

A substance made up of only one type of atom

Question 25

Calcium is an element. What type of atoms is it made out of?

Answer 25

Calcium atoms

Question 26

Like helium, argon is a noble gas. What structure would you expect argon to have?

Answer 26

Single atoms

Question 27

The noble gases all exist as _

Answer 27

single atoms

Question 28

Phosphorus is an element in which the atoms often bond together in groups of four. What is each group called?

Answer 28

A molecule

Question 29

Molecule

Answer 29

Small groups of atoms held together by chemical bonds

Question 30

T/F: A chemical bond is an attractive force that binds molecules to other molecules

Answer 30

False

Question 31

Which state or states are metal elements found in at room temperature?

Answer 31

- Solid - Liquid

Question 32

Most metals are found as ___ at room temperature

Answer 32

solids

Question 33

Which metal is found as liquid at room temperature?

Answer 33

Mercury

Question 34

Properties of metals

Answer 34

- Shiny or glossy - Conduct electricity - Can be flattened into sheets - Can be stretched into threads or wires

Question 35

T/F: Metals are malleable

Answer 35

True

Question 36

Chemical Mixture

Answer 36

A combination of substances that can be physically separated

Question 37

T/F: Most of the substances within and around us are made up of more than one type of atom.

Answer 37

True

Question 38

Most things are made up of ___.

Answer 38

compounds

Question 39

In what ways can atoms in compounds be arranged?

Answer 39

- Molecules - Lattices

Question 40

Water is a compound because it is made up of:

Answer 40

atoms of two elements, hydrogen and oxygen, chemically combined

Question 41

T/F: There is only ever one way that two elements can combine to form a compound

Answer 41

False

Question 42

Exothermic

Answer 42

Reactions that release energy

Question 43

The reaction between magnesium and hydrochloric acid is classified as exothermic because it:

Answer 43

releases energy in the form of heat

Question 44

Endothermic

Answer 44

Reactions that absorb energy

Question 45

Endothermic reactions _____ energy

Answer 45

absorb

Question 46

Endothermic reactions cause a _______ in temperature

Answer 46

decrease

Question 47

Activation energy

Answer 47

The energy required to break bonds

Question 48

Breaking chemical bonds ______ energy

Answer 48

requires

Question 49

Making chemical bonds _____ energy

Answer 49

releases

Question 50

T/F: All chemical reactions absorb energy and release energy

Answer 50

True

Question 51

atom

Answer 51

The smallest particle of an element

Question 52

molecule

Answer 52

A group of atoms bonded together

Question 53

Chemical bond

Answer 53

An attractive force that holds two atoms together

Question 54

Mixture

Answer 54

A combination of substances that can be physically seperated

Question 55

Physical change

Answer 55

A change in matter that does not form new substances

Question 56

Chemical Reaction

Answer 56

A change in matter that forms one or more new substances

Question 57

Products

Answer 57

The new substances produced by a chemical reaction

Question 58

T/F: Every chemical reaction has multiple reactants and multiple products.

Answer 58

False

Question 59

T/F: There are different elements present after a chemical reaction than before it

Answer 59

False

Question 60

Chemical equation

Answer 60

A representation of a chemical reaction

Question 61

Word equation

Answer 61

The simplest type of chemical equation uses the names of the substances

Question 62

law of conservation of matter

Answer 62

No atoms are created or destroyed. So the number of atoms of each element stays the same.

Question 63

Unbalanced equation

Answer 63

when there are unequal numbers of atoms of an element on either side

Question 64

Balanced equation

Answer 64

when there are equal numbers of atoms of each element on either side

Question 65

T/F: The law of conservation of matter states that the number of each type of atom does not change during a chemical reaction

Answer 65

True

Question 66

Coefficient

Answer 66

A number placed before a chemical formula