Atomic Structure and the Periodic Table

Question 1

What is an atom?

Answer 1

The smallest part of an element that can exist

Question 2

What is a proton?

Answer 2

A subatomic particle with a positive charge

Question 3

What is an electron?

Answer 3

A subatomic particle with a negative charge

Question 4

What is a neutron?

Answer 4

A subatomic particle with a neutral charge

Question 5

Describe the charge of an atom

Answer 5

It is neutral, or has no overall charge, as the charges of the protons and electrons balance out

Question 6

How do protons and electrons balance each other out?

Answer 6

The charges on each are the same size but opposite, so they cancel each other out

Question 7

What does the atomic number of an element tell you?

Answer 7

it tells you the number of protons in one atom of that element - the atomic number is how you identify each element

Question 8

What does the mass number tell you?

Answer 8

How many protons and neutrons there are total in the atom

Question 9

What is an element?

Answer 9

A substance made up of only atoms with the same atomic number

Question 10

What happens to atoms when they gain or lose electrons?

Answer 10

They become ions

Question 11

What is an ion?

Answer 11

A charged particle that has either gained or lost electrons, making them cations or anions

Question 12

What is an isotope?

Answer 12

A form of the same element with a different number of neutrons but the same number of protons.

Question 13

What is relative atomic mass?

Answer 13

An average mass taking into account all the different masses and abundances of all the isotopes that make up the element

Question 14

Why is relative atomic mass used?

Answer 14

Because many elements can exist as a number of different isotopes, so when referring to the element as a whole it is better to be representative

Question 15

What is the equation to work out relative atomic mass?

Answer 15

Question 16

What is a molecule?

Answer 16

2 or more atoms, held together by chemical bonds

Question 17

What is a compound?

Answer 17

2 or more elements, held together by chemical bonds. They are always found in fixed specific proportions.

Question 18

Can a molecule be a compound?

Answer 18

Yes, for example water is a molecule but is also a chemically bonded compound

Question 19

Describe the properties of compounds compared to the original elements?

Answer 19

Normally, the properties of the compound are totally different to those of the elements that make it up

Question 20

Describe the properties of mixture compared to the original elements?

Answer 20

The properties of a mixture are just a mixture of the properties of the separate parts of it

Question 21

What is a mixture?

Answer 21

Two or more elements and/or compounds mixed together with no chemical bonds between them

Question 22

What is chromatography used for?

Answer 22

It is used to separate compounds out of a mixture, e.g. to separate dyes out of an ink

Question 23

How does chromatography work?

Answer 23

Each substance in the mixture moves up the chromatography paper at different rates specific to that substance, allowing us to identify each one

Question 24

How does filtration work?

Answer 24

It traps an insoluble solid in the filter paper and allows the rest to past through

Question 25

What are the two methods to separate soluble solids from solutions?

Answer 25

Evaporation and crystallisation

Question 26

What is the process of evaporation?

Answer 26

Pour the solution into an evaporating dish and slowly heat it until the solvent starts to evaporate and the remaining solution becomes more concentrated. Continue the process until dry crystals are formed in the basin

Question 27

What is the process of crystallisation?

Answer 27

Pour the solution into an evaporating dish and slowly heat until the solvent starts to evaporate, or until crystals start to form (point of crystallisation). Then remove the dish from the heat and leave it to cool. The salt should form crystals as it becomes insoluble in the cold concentrated solution. Filter the crystals out and leave them to dry

Question 28

Why would you used crystallisation over evaporation and vice versa?

Answer 28

Evaporation is really quick, but can only be used if the salt doesn't decompose when heated. This is when crystallisation is used, and crystallisation also produces bigger crystals

Question 29

Describe how simple distillation works

Answer 29

The solution is heated and the substance with the lowest boiling point evaporates first. The vapour is then cooled, condenses in the condenser and collected.

Question 30

What is a restriction of simple distillation?

Answer 30

You can only use it to separate things with very different boiling points

Question 31

Compare the number of valence electrons of group 1, 7 and 0

Answer 31

Group 1 have one outer electron, group 7 have 7, and group 0 have 8 (except Helium has 2)

Question 32

Compare the reactivity trend of groups 1, 7 and 0

Answer 32

Group 1 - increases going down the group Group 7 - decreases going down the group Group 8 - all very unreactive

Question 33

What type of elements are found in group 1, 7 and 0?

Answer 33

Group one are metals, 7 and 0 are non-metals

Question 34

What is the physical state of elements in group 1, 7 and 0 at room temp?

Answer 34

G1 - soft solids G7 - Varies going down (F and Cl are gases, Br is liquid and I is solid) G0 - all gases

Question 35

Compare the densities of groups 1, 7 and 0?

Answer 35

G1 - low generally, but increases down the group G7 - Varies, but generally low G0 - Very low but increases down the group

Question 36

Compare group 1, 7 and 0 in a reaction with water

Answer 36

Group 1 react vigorously, producing hydrogen gas and an alkali Group 7 and 0 don't react with water

Question 37

Compare group 1, 7 and 0 in a reaction with oxygen

Answer 37

G1 - forms metal oxides G7 - forms non-metal oxides G0 - no reaction

Question 38

Describe the formation of ions in G1, G7 and G0

Answer 38

G1 - Forms +1 ions by losing 1 electron G7 - Forms -1 ions by gaining one electron G0 - Does not form ions

Question 39

Compare the bonding and compounds formed in groups 1, 7 and 0

Answer 39

G1 - forms ionic compounds with nonmetals G7 - forms ionic with metals, and covalent with non-metals G0 - rarely forms compounds

Question 40

List some uses of group 1 elements

Answer 40

Batteries, fireworks, sodium lamps

Question 41

List some uses of group 7 elements

Answer 41

Disinfectants, bleach, water treatment

Question 42

List some uses of group 0 elements.

Answer 42

Neon lights, helium balloons, inert atmospheres

Question 43

What is group 1 known as?

Answer 43

The alkali metals

Question 44

What is group 7 known as?

Answer 44

The halogens

Question 45

What is group 0 known as?

Answer 45

The noble gases

Question 46

How and why did Mendeleev arrange his Periodic Table with gaps left open?

Answer 46

- he arranged them in terms of atomic mass and properties, because protons hadn't been discovered (so not atomic number) - For some elements he switched them across group numbers to better align with the trend in their chemical and physical properties - He left gaps where he predicted undiscovered elements would fit, and predicted the atomic masses and properties of these missing elements