Atomic Structure and The Periodic Table

Question 1

What is an Element

Answer 1

A substance that contains only one type of atom

Question 2

What is a compound

Answer 2

A substance that contains atoms of two or more elements which are chemically combined

Question 3

What is a Mixture

Answer 3

two or more elements or compounds which are not chemically combined

Question 4

What is filtration used for

Answer 4

to separate soluble solids from insoluble solids

Question 5

What is Crystallisation used for

Answer 5

to obtain a soluble solid from a solution

Question 6

What and how is simple distillation used

Answer 6

Used to obtain a solvent from a solution

• Boil a set volume of water so that it changes into gas
• Water collects into the condenser and changes from a gas to liquid collected in a baker

Question 7

What is fractional Distillation used for

Answer 7

to separate mixtures in which they components have different boiling points

Question 8

What is the Atomic Number

Answer 8

The number or protons

Question 9

What is the mass number

Answer 9

No. protons + No. neutrons

Question 10

What is an isotope

Answer 10

Atoms of an element with the same number of protons but a different number of neutrons

Question 11

What ions do metals form

Answer 11

They loose electrons to form positive ions

Question 12

Why is a negative ion formed when an electron is gained

Answer 12

Gaining an electron means the overall charge will be -1 (negative) as there is one less positive proton - vice versa

Question 13

What ions do non-metals from

Answer 13

they gain electrons to form a negative ion

Question 14

What were the problems with John Newlands model of the periodic table and how did Mendeleev fix it
-after subatomic particles were discovered

Answer 14

• Newlands model strictly followed atomic weight which meant some of the elements were in the wrong place
• Mendeleev realised some elements were yet to be discovered so left gaps and reordered some elements
• Placed in groups with similar properties
• When subatomic particles were discovered it revealed he had organised them in increasing atomic number

Question 15

What are the group 0 elements named as and what makes them unreactive

Answer 15

Noble gases

• have a full outer shell so very table electron configuration
• boiling points increase down the group

Question 16

What are the properties of group 1 metals and what happens when they react with water

Answer 16

• the have low melting and boiling points
• alkali metals
• potassium + water —> potassium hydroxide + hydrogen
• produces a alkaline solution
• low densities (lithium, sodium and potassium float on water as they are less dense than it)

Question 17

Why do Group 1 metals become more reactive down the group

Answer 17

The electron gets further away from the influence of the nucleus so can be lost more easily

Question 18

What happens when group 1 alkali metals react with non-metals

Answer 18

They form ionic compounds where the metal atom looses one electron to from a metal ion with a positive charge

Question 19

Why does reactivity decrease down the group 7

Answer 19

The outer shell becomes further away from the influence of the nucleus and is shielded by more electrons making it harder to gain an electron.

Question 20

What happens when group 7 halogens react with metals

What happens when a more reactive halogen reacts with a less reactive one

Answer 20

They form ionic salts - the halogen atom gains one electron to form a halide ion with a negative charge
A more reactive halogen displaces a less reactive one to form an aqueous solution of its salts

Question 21

What happens when a more reactive halogen reacts with a less reactive one

Answer 21

It will displace it to from an aqueous solution of its salts

- Chlorine will displace bromine from potassium bromide

Question 22

What charges do transition metals have and what can the be used for

Answer 22

They have ions with different charges

Can be used as catalysts and are good conductors of heat and electricity