Scientists have hypothesized that oxygen began to build up in the Earth's atmosphere after the development of living things with the ability to

a. breathe air.

b. form tissues.

c. photosynthesize.

d. reproduce sexually.

Which property would be used to identify a compound in the laboratory?

How does pressure affect the solubility of a gas

The action is: earth pulls on moon. what is the reaction?

Calculate the theoretical yield in moles of magnesium chloride when 37 grams of Mg (s) react with 38 grams of HCl (aq). Write the answer using 2 decimal places and do not use scientific notation.

What is the difference between xylem and phloem? A. Xylem carries water and nutrients up to the plants leaves while phloem carries food down form the plants leaves to its roots B Xylem carries water and nutrients up to the plants leaves while phloem

A container with a volume of 3.46 liters contains a gas at a pressure of 1.30 atmospheres and a temperature of 274.27 Kelvins. How many moles of gas are in the container?

Benzene, C6H8, has an enthalpy of fusion = 10.19 kJ/mol. Calculate the amount of energy which is needed to change 88.0 g of solid benzene at 5.53°C into liquid benzene, also at 5.53°C?

What is the H3O + ion concentration of a solution that has an OH - ion concentration of 1.0 * 10^-3M? A) 1.0 * 10^-3M B) 1.0 * 10^-7M C) 1.0 * 10^-11M D) 1.0 * 10^-14M

Given the following chemical reaction: 2 O2 + CH4 CO2 + 2 H2O In the reaction of 6 moles of CH4 with excess oxygen, how many moles of water could be produced? 6 C 12.01 Carbon 1 H 1.01 Hydrogen 8 O 16.00 Oxygen A. 4 B. 6 C. 8 D. 12

Most mutagens have what kind of an effect on an organism?