chemistry topic one

Question 1

what does the nucleus contain

Answer 1

protons and neutrons

Question 2

what is the relative mass and electric charge of a proton

Answer 2

relative mass: 1
electric charge: +1

Question 3

what is the relative mass and electric charge of a neutron

Answer 3

relative mass: 1
electric charge: 0

Question 4

what is the relative mass and electric charge of a electron

Answer 4

relative mass: 0
electric charge: -1

Question 5

what is the mass number

Answer 5

number of protons + neutrons

Question 6

what is the atomic number

Answer 6

Number of Protons
OR electrons

Question 7

what is the formula for relative atomic mass (Ar)

Answer 7

Ar = (Ar of isotope 1 x Abundance of isotope 1) + (Ar of isotope 2 x Abundance of isotope 2)

100

Question 8

what is an isotope

Answer 8

forms of an element that have Same number of protons but different number of neutrons

Question 9

describe the structure of electrons in an atom

Answer 9

-The 1st shell maximum of 2 electrons
-The 2nd shell maximum of 8 electrons
-The 3rd shell maximum of 8 electrons

Question 10

what is an ion

Answer 10

An ion is an atom that gains or loses electrons

Question 11

what happens when an ion looses an electron

Answer 11

it becomes positively charged

Question 12

what happens when an ion gains an electron

Answer 12

it becomes negatively charged

Question 13

What type of ions do metals form?

Answer 13

positive ions

Question 14

who discovered atoms

Answer 14

John
Dalton

Question 15

What type of ions do non – metals form?

Answer 15

negative ions

Question 16

who Discovered electrons

Answer 16

JJ Thomson

Question 17

what did Ernest
Rutherford discover

Answer 17

Atoms made of a nucleus (protons) with
electrons orbiting it.

Question 18

who Discovered electron shells

Answer 18

Neils Bohr

Question 19

what was the Rutherford scattering experiment

Answer 19

Alpha particles (with a positive charge) where shot at a thin gold foil most particles passed right through but some where reflected showing that an atom is made up of a small, positively
charged nucleus surrounded by electrons orbiting

Question 20

who Discovered neutrons

Answer 20

James Chadwick

Question 21

why do group 1 atoms get more reactive down the group

Answer 21

• Atoms get larger down the
  group
• Outer electron gets further
  from the positive attraction of
  the nucleus
• Easier to lose the outer
  electron as you go down the
  group
• Making them more reactive

Question 22

why do group 7 atoms get less reactive down the group

Answer 22

-Atoms of each element get larger
going down the group.

• Outer shell gets further away
  from the nucleus
• Reduces the force of attraction
• Makes it more difficult to attract
  another electron

Question 23

what are chemicals in group 0 called

Answer 23

noble gases

Question 24

why can group 0 elements not react

Answer 24

because they have a full outer shell

Question 25

give some features of transition metals

Answer 25

High melting points, High densities, Shiny, Malleable, Strong, good conductors

Question 26

what group are alkali metals in

Answer 26

group 1

Question 27

what is a mixture

Answer 27

A mixture consists of two or more elements or compounds not chemically combined together.

Question 28

what does filtration do

Answer 28

separates insoluble substances from a solvent e.g.
sand from water

Question 29

what is Crystallisation

Answer 29

This technique separates a soluble substance from a solvent by evaporation

Question 30

what is Simple distillation

Answer 30

This technique separates a liquid from a mixture by evaporation followed by condensation

Question 31

what is Chromatography

Answer 31

This technique separates small
amounts of dissolved substances by running a solvent along absorbent paper

Question 32

describe fractional distillation

Answer 32

a mixture is put into a fractional column which is hot at the bottom and cool at the top Substances with high boiling points condense at the bottom and substances with low boiling points condense at the top.