At the carnival, a baby was given a helium balloon whose pressure equaled the atmospheric pressure at the carnival which was 102.7 kPa. However, the baby wasn't
paying attention and the balloon floated away into the troposphere where the
atmospheric pressure is 97.8 kPa. What is the positive difference between the
pressure in the balloon and the pressure of the troposphere in atm?
atm

Here's link to the

tinyurl.com/wpazsebu

in chemistry, a solution’s concentration is how much of a dissolvable substance, known as a solute, is mixed with another substance, called the solvent. the standard formula is c = m/v, where c is the concentration, m is the mass of the solute dissolved, and v is the total volume

it's c. elements are placed in rows based on how may valencies electrons have.