Chemistry assessment September 2016

Question 1

Atoms are surrounded by what?

Answer 1

Electrons

Question 2

What is each atom made up off?

Answer 2

A nucleus which contains protons and neutrons

Question 3

What is the atomic number?

Answer 3

The number of protons in an atom

Question 4

How are the elements arranged in the periodic table?

Answer 4

In ascending order of atomic number

Question 5

The mass number of an atom is what?

Answer 5

Total of protons and neutrons

Question 6

Atoms of the same element with different numbers of neutrons are called?

Answer 6

Isotopes of that element

Question 7

Protons and electrons are what?

Answer 7

Oppositely charged

Question 8

Do neutrons have a charge?

Answer 8

No, they have no charge

Question 9

Nucleus of an atoms is always…

Answer 9

Positively charged

Question 10

Why does an atom have a neutral overall charge?

Answer 10

It has the same number of electrons as protons

Question 11

Protons and neutrons have what?

Answer 11

The same mass

Question 12

What is the atomic number?

Answer 12

The number of protons in an atom

Question 13

What is the mass number?

Answer 13

Total number of protons and neutrons in an atom

Question 14

Where is the mass number shown on a chemical symbol?

Answer 14

At the top

Question 15

Where is the atomic number shown on a chemical symbol?

Answer 15

At the bottom

Question 16

What is the isotope of carbon?

Answer 16

-12 or 12C

Question 17

How do you find out the neutron number on a chemical symbol?

Answer 17

Top number take away the bottom

Question 18

What did John Dalton do?

Answer 18

He did experiments
Worked out some atomic weights
Invented symbols for atoms and molecules

Question 19

Some of Dalton’s conclusions…

Answer 19

All matter is made from atoms
Atoms cannot be broken down into anything simpler.
Atoms are rearranged in a chemical reaction.

Question 20

When was the electron discovered?

Answer 20

1897 by Jj Thompson

Question 21

What did Jj show us?

Answer 21

That atoms contained smaller pieces

Question 22

Ernest Rutherford showed us?

Answer 22

Experiments to show that an atom must contain a central nucleus

Question 23

In an early model, the atom was imagined as what?

Answer 23

A sphere of positive charge with negatively charged electrons.

Question 24

Radius of a typical atom?

Answer 24

10-10m

Mass- 10-23

Question 25

The mass number of an atom is…

Answer 25

Never smaller than the atomic number.

It can be the same

Question 26

The number of protons and neutrons in an atom is what?

Answer 26

The same

Question 27

What charge do electrons have?

Answer 27

Negative charge

Question 28

What happens if electrons are added or removed?

Answer 28

The atoms become charged and then is an ion

Question 29

If a substance contains only one type of atom it is called an?

Answer 29

Element

Question 30

What are isotopes?

Answer 30

Are atoms of an element with the normal number of protons and electrons but different numbers of neutrons

Question 31

Isotopes have the same atomic number but

Answer 31

different mass number

Question 32

The rate of reaction can be measured by what?

Answer 32

Rate at which a reactant is used up

Product is formed

Question 33

Factors which affect the rate of reaction?

Answer 33

Temp
Concentration 
Pressure of reacting gases
Surface area
Catalysts

Question 34

Chemical reactions can only happen if?

Answer 34

Reactant particles collide with enough energy

Question 35

Things to measure?

Answer 35

The mass of a substance (balance)

The volume of gas (gas syringe)

Question 36

To increase the rate of reaction the concentration of a dissolved reactant is?

Answer 36

Increased

Question 37

To increase the rate of reaction the pressure of reacting gas is?

Answer 37

Increased

Question 38

To increase the rate of reaction solid reactants are?

Answer 38

Broken into smaller pieces

Question 39

The minimum energy needed for particles to react is called the?

Answer 39

Activation energy