6. explain why the boiling point of water is a characteristic physical property, but the temperature and volume of a glass of water are not.

The physical property is a physical characteristic of a substance at some given conditions

for example

The density of water is 1 g/ mL at STP

The boiling point of water is 373K at 1 atm pressure

so boiling point of water is its physical property. It does not change with amount of the substance. The boiling point of water will remain the same for 1g and 1kg etc

now temperature is an instant measurement, the temperature may vary from sample to sample. Some water sample can be cool or some can be hot. So we cannot define that temperature of all water sample at a given pressure will be the same.

similarly the volume is a not a physical property. It will change from amount to amount.

1g of water sample will have different volume and 100g of water will have different volume while the density of water will remain the same.

the answer is 1 i believe