Why it is advisable to use pressure cooker at high altitude for cooking food?

You may expect bonds between two atoms which each have n covalent lonic metallic hydrogen

A100-watt light bulb radiates energy at a rate of 100 j/s. (the watt, a unit of power or energy over time, is defined as 1 j/s.) if all of the light emitted has a wavelength of 525 nm , how many photons are emitted per second?

What is the molarity of the solution produced when 145 g of nacl is dissolved in sufficient water to prepare 2.75 l of solution?