Describe each of the following as a physical or chemical property.

1. Apple slices turn brown when exposed to air.
2. At room temperature, mercury is a liquid.
3. Phosphorus will ignite when exposed to air.
4. Neon is a colorless gas at room temperature.

Explanation:

Physical change -

It refers to any change during any process , where there is no new substance is formed , is referred to as a physical change.

Any change in the state of matter is characterised under physical change.

Chemical change -  

It refers to any change in a chemical process , where there is formation of any new substance , is referred to as a chemical change .

From the options given in the question,

1. Apple turning brown , on air exposure , is an example of chemical change .

2. The physical state of mercury is liquid ,  is an example of physical change .

3. phosphorus burns on exposed to air , is an example of chemical change .

4. The gas Neon is colorless at the room temperature , is  is an example of physical change .

thats how its supposed to be