Chemistry

Question 1

what charge do electrons have?

Answer 1

Negative

Question 2

Why did Mendeleev leave gaps in his periodic table

Answer 2

For elements that had not yet been discovered

Question 3

Why is group 0 highly unreactive

Answer 3

They have a stable arrangement of electrons (full outer shell)

Question 4

Sodium + water —>

Answer 4

Sodium hydroxide + hydrogen

Question 5

Sodium + chloride —>

Answer 5

Sodium chloride

Question 6

Sodium + oxygen

Answer 6

Sodium oxide

Question 7

State the trend in boiling point down group 7

Answer 7

increases down the group

Question 8

Potassium bromide + Chlorine —>

Answer 8

Potassium chloride + bromine

Question 9

What type of reaction is this? Potassium bromide + chloride —> Potassium + bromine

Answer 9

Displacement reaction

Question 10

How do you calculate the number of neutrons in an atom?

Answer 10

Mass number minus atomic number

Question 11

what is an ion?

Answer 11

an atom which has lost or gained electrons

Question 12

how many electrons can go in the first shell?

Answer 12

2

Question 13

how many electrons can go in the second and third shell?

Answer 13

8

Question 14

what is the definition of a displacement reaction?

Answer 14

A more reactive element will displace a less reactive element from a compound

Question 15

are the halogens metals or non-metals?

Answer 15

non-metal

Question 16

what colour flame is produced when potassium reacts with water?

Answer 16

lilac

Question 17

group 7 are diatomic, what does this mean?

Answer 17

They exist in molecules made up of pairs of atoms e.g Br2

Question 18

State the colour and state of chlorine at room temperature

Answer 18

green gas

Question 19

state the colour and state of iodine at room temperature

Answer 19

Grey solid

Question 20

What happens to the number of electron shells down the group?

Answer 20

increase in the number of shells

Question 21

state the charge of all elements in group 1 when they become ions

Answer 21

+1

Question 22

State the charge of all the elements in group 7 when they become ions

Answer 22

-1

Question 23

Explain why group 1 gets more reactive down the group

Answer 23

Atoms get bigger down the group. Electrons is further away from the nucleus. Lose an electron more easily.

Question 24

Explain why group 7 gets less reactive down the group

Answer 24

More shielding down the group. Atoms get bugger down the group. Electron further way from nucleus. Electrons is gained less easily.

Question 25

What will you observe when sodium reacts with water?

Answer 25

Fizzes, melts, floats, moves and the surface disapears

Question 26

why did Mendeleev put some elements in groups?

Answer 26

Because they had similar chemical properties

Question 27

define atom

Answer 27

The smallest part of an element that can still be recognised as that element

Question 28

define element

Answer 28

A substance made of only one type of atom

Question 29

define compound

Answer 29

A substance made of two or more different atoms chemically bonded together

Question 30

What does soluble mean?

Answer 30

dissolvable in water

Question 31

what does insoluble mean?

Answer 31

not dissolvable in water

Question 32

describe the plum pudding model

Answer 32

A ball of positive charge with ELECTRONS embedded in it

Question 33

What scientist developed the plum pudding model?

Answer 33

JJ Thomson

Question 34

What discovery did the alpha particle scattering experiment (gold foil) lead to?

Answer 34

The atoms have a dense nucleus with a positive charge

Question 35

What did Bohr propose about electrons

Answer 35

electrons orbit at set energy levels

Question 36

What scientist provided evidence for neutrons in the nucleus?

Answer 36

James Chadwick

Question 37

State the tree subatomic particles

Answer 37

Protons neutrons and electrons

Question 38

State the MASSES of the subatomic particles

Answer 38

Proton=1 neutrons=1 electrons= very small

Question 39

State the RELATIVE CHARGES of subatomic particles

Answer 39

Protons= +1 neutrons= 0 electrons=-1

Question 40

How are the subatomic particles arranged in an atom?

Answer 40

Protons and neutrons in the nucleus, electrons orbiting the shells

Question 41

What is an isotope?

Answer 41

Atoms of the same element with a different number of neutrons

Question 42

What is the overall charge of an atom neutral?

Answer 42

There are the same number of protons (positive) as electrons (negative)

Question 43

State the overall charge of the nucleus. Why?

Answer 43

Positive, only made up of protons and neutrons.

Question 44

What is the ATOMIC number of an atom?

Answer 44

The number of protons in an atom

Question 45

What is the MASS number of an atom?

Answer 45

The number of protons and neutrons

Question 46

What is the name of group 1?

Answer 46

The alkali metals

Question 47

What is the name of group 7?

Answer 47

the halogens