Atoms, elements and compounds

Question 1

What is the mass and charge of a proton?

Answer 1

Mass: 1 unit
Charge: +1

Question 2

What is the mass and charge of a neutron?

Answer 2

Mass: 1 unit
Charge: no charge

Question 3

What is the charge of an electron?

Answer 3

Charge: -1

Question 4

What is the proton number/atomic number?

Answer 4

number of protons in nucleus of atom

Question 5

What is the nucleon number?

Answer 5

number of protons and neutrons in the nucleus of an atom/relative atomic mass

Question 6

What do columns in a periodic table show?

Answer 6

groups with similar reaction properties

Question 7

What do rows in a periodic table show?

Answer 7

periods

Question 8

What are isotopes?

Answer 8

atoms of same element with same proton number, different number of neutrons → different nucleon number

Question 9

Why do isotopes have the same properties?

Answer 9

same properties because same number of electrons in outer shell

Question 10

What are the two types of isotopes?

Answer 10

radioactive

non-radioactive

Question 11

What are some medical and industrial uses for radioactive isotopes?

Answer 11

Medical: cancer treatment, locating tumours
Industrial: check for oil and gas leaks

Question 12

What is oxidation state/valency number?

Answer 12

number of electrons in outer shell

Question 13

Why is group 0 unreactive?

Answer 13

full outershell

Question 14

Why do atoms with more electron shells have higher energy levels?

Answer 14

Further away from nucleus

Question 15

What is an ion?

Answer 15

electrically charged particle

Question 16

What is an ionic bond made of?

Answer 16

Metals + Non-metals

Question 17

How are ionic bonds formed?

Answer 17

Atoms lose/gains electrons to become stable

Question 18

What is the structure of ionic bonds?

Answer 18

arranged in a giant lattice with regular pattern of particles held together by strong ionic bonds

Question 19

What are the properties of ionic compounds (5)?

Answer 19

High boiling + melting points (ionic bonds strong)
Poor conductors as solid (no free electrons/ions)
Conducts electricity as liquid
Hard
Soluble in water

Question 20

Why do ionic compounds have high fixed points?

Answer 20

ionic bonds strong, lots of energy required to overcome electrostatic attraction

Question 21

Why do ionic compounds conduct electricity as liquid?

Answer 21

charged ions free to move

Question 22

What is a covalent bond made of?

Answer 22

Non-metal + Non-metal

Question 23

What are molecules?

Answer 23

a group of atoms held together by COVALENT bonds

Question 24

How are covalent bonds formed?

Answer 24

Atoms share pairs of electrons to achieve noble gas configuration

Question 25

What is the strength of bonding in covalent bonds ?

Answer 25

Molecular bonds strong, intermolecular are weak

Question 26

What are the properties of covalent compounds?

Answer 26

Low melting/boiling points Don’t conduct electricity (not charged) Insoluble in water, but dissolve in organic solvents

Question 27

Why do covalent compounds have low fixed points?

Answer 27

weak intermolecular forces

Question 28

How many electrons are shared in a single, double and triple covalent bond?

Answer 28

Single bond: 2 electrons shared (1 from each atom) Double bond: 4 electrons shared (2 from each atom) Triple bond: 6 electrons shared (3 from each atom)

Question 29

Why do giant covalent structures have high fixed points?

Answer 29

structure made up of strong covalent bonds

Question 30

Why don't giant covalent structures conduct electricity?

Answer 30

have no mobile ions or electrons, except for graphite

Question 31

What are the properties of diamond? (4)

Answer 31

Shares 4 valence electrons → 3D lattice Strong covalent bonds High fixed points Forms tetrahedron

Question 32

What are the properties of graphite? (6)

Answer 32

Shares 3 valence electrons 4th electron free -- Free moving electrons Strong covalent bonds Held together by weak forces so is soft and slippery -used as a lubricant Slide over each other

Question 33

What are the properties of silicon dioxide? (5)

Answer 33

``` Makes up sand Each Si is bonded to 4 oxygen atoms Each oxygen bonded to 2 silicon atoms High fixed points Hard ```

Question 34

What are delocalized electrons

Answer 34

Free electrons in metallic bonding

Question 35

Why can metals conduct electricity and heat?

Answer 35

Delocalized electrons can carry charge

Question 36

Why are metals malleable + ductile?

Answer 36

attractive forces between metal ions and electrons act in any direction -- when layers slide new bonds can easily form