Which of the following are kept as a constant in Boyle's law (check all that apply)
volume
temperature
amount
pressure
none of these

temperature

amount

Explanation:

Under the postulate of Boyle's law, both temperature and amount(number of moles) are kept constant.

  According to Boyle's law "the volume of a fixed mass of gas varies inversely as the pressure changes if the temperature is constant"

 Based on the premise of this law, both temperature and amount of substance is kept constant.

the answer is b & c i believe : )