Group 7 and Group 1

What do halogens have in common regarding their outer shell electrons?

Halogens have 7 outer shell electrons.

what colour flame does lithium turn to?

red

what colour flame does sodium turn to?

yellow

what colour flame does potassium turn to?

purple

what colour flame does calcium turn to?

brick red

what colour flame does barium turn to?

apple green

What happens to the reactivity of halogens as you move down the group?

Elements become less reactive down the group.

What is the state of chlorine at room temperature?

Chlorine is a gas.

What is the state of bromine at room temperature?

Bromine is a liquid.

What is the state of iodine at room temperature?

Iodine is a solid.

What is the use of chlorine in water treatment?

Chlorine kills bacteria in swimming pools and drinking water.

What is iodine used for in hospitals?

Iodine is used as an antiseptic in hospital procedures.

What is the result of the silver nitrate test for chloride ions?

A white precipitate forms.

What is the result of the silver nitrate test for bromide ions?

A cream precipitate forms.

What is the result of the silver nitrate test for iodide ions?

A yellow precipitate forms.

What is a displacement reaction?

A displacement reaction occurs when a more reactive element replaces a less reactive element in a compound.

What is the percentage yield formula?

Percentage yield = (actual mass / theoretical mass) x 100.

How do you calculate the molar mass (Mr) of a compound?

Add the atomic masses of all atoms in the molecular formula.

What is the molar mass of ammonium nitrate (NH4NO3)?

The molar mass is 80 g/mol.

What is the simplest formula for a compound with 32g of copper and 4g of oxygen?

The simplest formula is Cu2O.

How do you calculate the number of moles from mass?

Number of moles = mass / molar mass.

What is the molar mass of iron pyrites (FeS2)?

The molar mass is 120 g/mol.

How many moles are in 80g of a compound if its molar mass is 160 g/mol?

There are 0.5 moles.

What happens to alkali metals as you move down the group?

They become more reactive as it becomes easier to lose an electron.

What is the reaction of lithium with water?

Lithium fizzes, skims the surface, floats, and produces lithium hydroxide and hydrogen gas.

What is the appearance of alkali metals when cut?

They are shiny when cut but become dull over time.

What is the universal indicator color in an alkali solution?

The universal indicator turns purple in an alkali solution.