Properties of a substance which can be measured or observed without altering the identity of the substance being measured are

the answer is chemical properites

Correct. chemical properties are the characteristic than an element or a compound that depends on one the particles that make it and not the structure or shape. in other words, these properties do not depend on the shape but what they compound is made of. 

some examples of chemical properties are toxicity and flammability

The answer is 323 g.

Ithink this is what you meant. the temperature at which a liquid begins to boil is called the boiling point. the boiling point of water is 212°f or 100°c.  and at that point will start to turn into steam (gas)