C1 - Atomic Structure and the Periodic Table

Question 1

What are the relative mass and charge of a proton?

Answer 1

mass = 1
charge = +1

Question 2

What are the relative mass and charge of a neutron?

Answer 2

mass = 1
charge = 0

Question 3

What are the relative mass and charge of a electron?

Answer 3

mass = ~0
charge = -1

Question 4

What does the mass number of an element tell you?

Answer 4

the total number of protons and neutrons

Question 5

What does the atomic number of an element tell you?

Answer 5

the number of protons

Question 6

Define isotope

Answer 6

Isotopes are different forms of the same element, which have the same number of protons but different number of neutrons (same atomic number but different mass number)

Question 7

Define atom

Answer 7

the smallest part an element can be broken down into

Question 8

Define element

Answer 8

made up of only one type of atom that are chemically bonded

Question 9

Define compound

Answer 9

two or more different atoms that are chemically bonded

Question 10

Define mixture

Answer 10

two or more different atoms that are not chemically bonded

Question 11

Describe how to do paper chromatography

Answer 11

• draw a line at the bottom of filter paper in pencil
• add a spot of ink and place in a beaker of solvent (not touching the ink)
• the solvent will seep up the paper with the ink
• the different dyes will move at different speeds so there will be spots

Question 12

Describe filtration

Answer 12

• it can be used if your product is an isoluble solid that needs to be separated from a liquid
• use a funnel and filter paper

Question 13

Describe evaporation

Answer 13

• use an evaporating dish to slowly heat the solution
• the solvent will evaporate and you will have small crystals
• it only works if the salt doesn’t decompose when heated

Question 14

Describe crystallisation

Answer 14

• use an evaporating dish to slowly heat the solution
• once crystals start to form remove dish from heat and leave to cool

Question 15

Describe distillation

Answer 15

Separating a solvent from a solution.
- the solution is heated - the part that has the lowest boiling point evaporates first
- the vapour is cooled and condensed in a condenser and collected in a different beaker

Question 16

Describe the history of the atom - plum pudding model

Answer 16

• 19th century = John Dalton thought atoms were solid spheres and he said different spheres make up different elements
• 1897 = J J Thompson discovered electrons and created the plum pudding model - ball of positive charge with electrons in

Question 17

Describe the history of the atom - Rutherford

Answer 17

• 1909 = Rutherford conducted the alpha scattering experiment (firing alpha particles at a thin sheet of gold)
• most particles went straight through, some were deflected and a few were deflected straight backwards
• Rutherford concluded most of the mass was concentrated in the centre and there was lots of empty space

Question 18

Describe the history of the atom - Bohr `

Answer 18

• Bohr suggested that electrons were found in shells at a fixed distance that orbit the nucleus

Question 19

What are the rules for electron shells?

Answer 19

• the shell closest to the nucleus is filled up first and contains 2 electrons max
• the next two shells contain 8
  electrons max

Question 20

How do you work out the electron structure?

Answer 20

• the atomic number (bottom number) = number of electrons
• figure out if it fills the first shell and the next shell
• write it like this: 2,8,1

Question 21

Describe the development of the periodic table - early 1800s

Answer 21

• they arranged elements in order of atomic weight (relative atomic mass)
• a periodic pattern was noticed in the properties of the element

Question 22

Describe the development of the periodic table - Mendeleev

Answer 22

• 1869 = Mendeleev made a table of elements with gaps - he put it in order of atomic weight but changed the order if the properties didn’t fit
• Mendeleev could predict properties of unknown elements because of the gaps

Question 23

Describe the modern periodic table

Answer 23

• elements are in order of increasing atomic number and there are periodic patterns of the properties
• elements with similar properties form columns called groups - group numbers tell you how many electrons there are on the outer shell
• metals are on the left and non-metals are on the right

Question 24

Describe transition metals

Answer 24

• centre of the periodic table
• typical metals (dense, shiny etc.)
• can have more than one ion
• often coloured
• make good catalysts

Question 25

Describe group 1 elements

Answer 25

• alkali metals
• have one electron on their outer shell
• soft and low density metals
• as you move down, the reactivity increases and the melting/boiling points decrease
• very reactive

Question 26

Why is potassium more reactive than sodium, in terms of electronic structure?

Answer 26

• as you move down group 1, the atom gets larger which means that the outer electron is further from the nucleus
• this decreases the electrostatic force of attraction between the negative electron and the positive nucleus
• so the bigger the atom = the outer electron is more easily lost = more reactive
• potassium is a larger atom than sodium

Question 27

Describe group 7 elements

Answer 27

• halogens - non-metals
• as you go down, they become less reactive and have higher melting/boiling points
• displacement reactions occur

Question 28

Describe group 0 elements

Answer 28

• noble gases - all gases
• have 8 electrons in outer shell
• unreactive
• as you move down, the boiling points increase