Chemistry unit 1

Question 1

What is an atom

Answer 1

The tiny particles that make up everything that exist

Question 2

What is a compound

Answer 2

A chemical reaction takes place and it creates a compound which has 2 or more elements chemically bonded together in fixed positions eg HCl

Question 3

What is a mixture

Answer 3

A substance made up of 2 or more elements that are not chemically bonded together. The substances in the mixture still have their own chemical properties

Question 4

What is the charge on protons neutrons and electrons

Answer 4

Proton= +1
Election=-1
Neutron=0

Question 5

What are the sizes of these particles

Answer 5

Proton=1
Neutron=1
Electron=1/2000

Question 6

What is the atomic number on an element

Answer 6

How many protons are in the nucleus

Question 7

What is the mass number on an element

Answer 7

The number of protons plus the number of neutrons

Question 8

How many electrons can go in each shell of an atom

Answer 8

Shell 1 = 2
Shell 2 = 8
Shell 3 =8

Question 9

Write out the electron configuration of sodium

Answer 9

(2,8,1)

Question 10

Write out the electron configuration for oxygen

Answer 10

(2,6)

Question 11

What is relative atomic mass

Answer 11

The average value that takes in the abundance of the isotopes of the element

Question 12

What is an isotope

Answer 12

An element with the same number of protons and electrons but a different number of neutrons

Question 13

What is an ion

Answer 13

An element that has lost or gained electrons in order to get a full outer shell and a charge

Question 14

What did John dalton suggest about the atom

Answer 14

They were matter that could not be created destroyed of divided
They were the smallest thing that things were made up of. Atoms of the same substance were identical

Question 15

What did J.J Thompson discover and how did this change the model of the atom

Answer 15

1897 J.J Thompson discovered the electron and proved that atoms could be divided into smaller particles.

Question 16

Describe J.J Thomson’s Plum Pudding Model

Answer 16

A solid ball of positive charge with negative electrons scattered throughout

Question 17

What experiment did Ernest Rutherford use to find the nucleus

Answer 17

Gold foil experiment- he shot an alpha ray at a thin gold foil and observed how it refracted

Question 18

What were his results

Answer 18

Most rays went straight through so the atoms was mostly empty space. Some deflected at small angles showing that the centre of the atoms had a positive charge. Some deflected straight back showing most of the atoms mass was concentrated in the centre

Question 19

How did Niels Bohr change Rutherfords nuclear atom model

Answer 19

He worked out that there were electron shells that stopped the positive nucleus and electrons collapsing and these shells were at set distances from the nucleus

Question 20

What did James Chadwick discover

Answer 20

He discovered the neutron by accounting for the missing weight inside the nucleus and this furthered our understanding of isotopes

Question 21

How do we order the periodic table

Answer 21

Groups: element that have similar properties are grouped together in columns
Periods: elements with the same amount of shells are in the same period. In general, elements are ordered by their atomic number

Question 22

Who created the arrangement of the current periodic table

Answer 22

Dimitri Mendeleev

Question 23

John Newlands law of octaves ?

Answer 23

He ordered his periodic table by atomic weight and this made it so every eighth element had similar properties but it was disproven due to its rigid structure

Question 24

How was Mendeleev’s table different

Answer 24

He left gaps for elements that would be discovered in the future and when new elements were discovered, they fit in the gaps which helped to to prove his table correct

Question 25

Metals vs non metals

Answer 25

Metals can make ions and are on the left of the periodic table and non metals are on the right side.

Question 26

Give the characteristics of group 1 alkali metals

Answer 26

Soft, very reactive, react with oxygen to make an oxide, increases with reactivity as it goes down the table

Question 27

Why does reactivity increases down the table

Answer 27

Atom size increases and so electrostatic attraction decreases with bigger atoms and so an atom is lost more easily

Question 28

Why do all elements want to gain a full outer shell configuration

Answer 28

So that they become unreactive like the group 0 elements/ noble gases as then it’s more stable

Question 29

Give characteristics of group 7 halogens

Answer 29

Diatomic non metals, form covenant bonds with non metals, 7 electrons in their outer shell, decreases in reactivity as you go down the table

Question 30

Give examples of halogens

Answer 30

Chlorine bromine iodine fluorine

Question 31

Typical properties of transition metals

Answer 31

Hard, good conductors, the same element can have different charges, high melting point, not very reactive, often used as catalysts

Question 32

Transition Metals Compared to group 1 metals

Answer 32

Harder, less reactive, higher melting point, more dense

Question 33

Lithium reaction with oxygen

Answer 33

Red flame

Question 34

Sodium reaction with oxygen

Answer 34

Orange flame

Question 35

Potassium reaction with oxygen

Answer 35

Purple flame