Chemistry

Question 1

What happens if some electrons are added or removed?

Answer 1

The atom becomes charged and is then an ion

Question 2

Sodium +chloride= sodium chloride

Answer 2

2Na (s) + Cl2 (g) = 2NaCl (s)

Question 3

What happens if an atom in group losses an electron?

Answer 3

It Forms positive ions

Question 4

What happens when an atom in group 7 gains an electron

Answer 4

It’s forms a negative ion

Question 5

Group 1- the alkali metals

Answer 5

Lithium
Sodium. More reactive as you
Potassium Go down the group because
Rubidium The outer electron is more
Caesium. Easily lost because it’s further
Francium. Away from the nucleus
-have a higher density
-have a lower melting and boiling Point

Question 6

Alkali metals

Answer 6

• soft metals
• shiny when cut but react wig oxygen and tarnish
• so reactive, has to be stored in oil, if not would react with water vapour in air

Question 7

When lithium sodium or potassium are put in water they react vigorously and produc hydrogen gas

Answer 7

Sodium+water=sodium hydroxide+hydrogen

2Na (s)+ 2H20(l) = 2naoh (Aq) + h2 (g)

Question 8

Group 7- halogens

Answer 8

Fluorine
Chlorine. As you go down the group
Bromine. Becomes less reactive because
Iodine. The outer electrons are further from.
Astatine. The nucleus so electrons are attracted
Less strongly
-have a higher melting and boiling point

Question 9

The halogens are non metals with coloured vapours

Answer 9

• Fluorine is a very reactive poisonous YELLOW gas at room temp and pressure
• Chlorine is a very reactive, poisonous dense GREEN gas at room temp and pressure
• bromine is a dense, poisonous, ORANGE volatile liquid at room temp and pressure and forms an ORANGE gas
• iodine is a dark GREY crystalline solid at room temperature or a purple vapour