Chemistry Yr 9 - Periodicity + Bonding

Question 1

Name the trends in Group 1?

Answer 1

Known as the Alkali Metals
Reactivity increases as you go down the group
metals
really reactive
melting + boiling point gets lower as you go down the group

Question 2

Name the trends in group 7?

Answer 2

Known as the halogens
reactivity decreases as you go down the group
more reactive halogen will replace a less reactive halide
Highly reactive
non metals

Question 3

Name trends in group 0?

Answer 3

known as the noble gases
unreactive
colourless and odourless
low melting points
non metals
non flammable
stable not needing to loose or gain electrons

Question 4

Name similarities between group 1 and 7

Answer 4

highly reactive.
Both groups form ionic compounds
Their elements react with other groups to achieve a full outer shell of electrons.

Question 5

What is ionic bonding?

Answer 5

the transfer of electrons between a metal and non-metal.
ionic bonds form between oppositely charged ions

Question 6

what is covalent bonding

Answer 6

atoms are held together by sharing pairs of electrons between non metals

Question 7

what is metallic bonding?

Answer 7

the electrostatic attraction between positive metal ions and a sea of delocalised electrons

Question 8

name the physical properties in the halogens?

Answer 8

strong covalent bonds
weak intermolecular forces
low melting and boiling points
poor conductors of heat and electricity

Question 9

Name the chemical properties of the halogens?

Answer 9

all have 7 electrons in their outer shell
they all want to gain one more electron to have a full outer shell either by ionically bonding or covalently bonding

Question 10

Name the physical properties of group1

Answer 10

have very low density
very soft
can be cut with a knife and then goes dull as it oxidises
needs to be stores in oil to stop it reacting with the water ion the air

Question 11

What did John Dalton contribute to the periodic table?

Answer 11

came up with the table of elements
elements where ordered by their atomic weights

Question 12

What did John Newlands contribute to the periodic table?

Answer 12

the law of octaves but broke down after calcium
built on Daltons ideas and arranged the known elements by atomic mass

Question 13

What did Dmitri Mendeleev contribute to the periodic table?

Answer 13

he arranged the elements according to atomic weight
he grouped elements with similar properties together
he left gaps for unknown elements and predicted what their properties would be when the elements where discovered they matched his predictions and his table was accepted by the scientific community

Question 14

Properties of metals

Answer 14

shiny
mostly solid
dense and strong
good heat
good electrical conductors

Question 15

properties of non metals

Answer 15

dull
low density
weak
brittle
poor heat
poor electrical conductor

Question 16

why was the periodic table being developed?

Answer 16

chemists tried to classify the elements it arranges them in an order which is similar elements are grouped together

Question 17

What are intermolecular forces?

Answer 17

they are weak forces if attractions between molecules influencing their physical properties like melting/boiling points and states of matter

Question 18

in group 0 does the boiling point increase or decrease as you go down the group?

Answer 18

increases

Question 19

What’s the modern name for atomic weight?

Answer 19

relative atomic mass

Question 20

Why did Mendeleev reverse the order of tellurium and iodine?

Answer 20

he reversed them as his periodic table was also based on the elements properties not just their atomic weight.

Question 21

Why did scientists reject Newlands ideas?

Answer 21

his law of octaves broke down after calcium
he put elements with different properties in the same group instead prioritising atomic weight
he didn’t leave gaps for unknown elements

Question 22

why did scientists accept Mendeleev’s ideas?

Answer 22

he accurately placed elements by their chemical properties and atomic mass
he left gaps for undiscovered elements
his predictions of unknown elements where accurate so when those elements where discovered they had a place on the table

Question 23

what happens when sodium reacts with chlorine?

Answer 23

produces bright yellow flame and releases heat
sodium loses one electron forming a positive ion and chlorine gains one electron forming a negative ion
this results in a stable ionic compound NaCl

Question 24

in a modern periodic table how are elements ordered?

Answer 24

by atomic number

Question 25

when anything is reacted with group one what gas is released?

Answer 25

hydrogen

Question 26

What state is astatine at room temperature?

Answer 26

Solid

Question 27

formula of astatine?

Answer 27

At2

Question 28

in a modern periodic table the elements are arranged in order of blank

Answer 28

atomic number

Question 29

what elements are often used as catalysts

Answer 29

transition metals

Question 30

name two differences you would see between the reactions of potassium and lithium with water

Answer 30

potassium reacts much faster as it moves around on the surface
potassium reacts more violently as its lower down the goup