The amount of heat required to change the temperature of 1 g of any substance by one °C is defined as .

Which property is used to identify the origin of an igneous rock? color density hardness crystal size

The oxidizing agent our bodies use to obtain energy from food is oxygen (from the air). if you breathe 15 times a minute (at rest), taking in and exhaling 0.5 l of air with each breath, what volume of air do you breathe each day? air is 21% oxygen by volume. what volume of oxygen do you breathe each day?

The first amino acid of a new polypeptide chain is