What does endothermic and exothermic mean?

The element "um" is what type of word element?

Scientific notation" to answer this question. Write the "full number" (aka. standard notation) for the following values: 7 E-8, 7 E8, 7 E-4. (site 1)

Should disel and gasoline engines complaint with CO2 emissions standards be banned? Can this statement be answered by science?

Which statement about atmospheric pressure near Earth's surface is true? a. It increases as you move away from Earth's surface. b. It decreases as you move away from Earth's surface. c. It is constant throughout Earth's atmosphere. d.

What mass of copper is consumed in the reaction with hydrochloric acid if 10.0 g of gas is collected?

How many experimental trials are needed before a hypothesis can be accepted as true?

The type of bonding that involves a transfer of electrons is

Calculate the molar mass of NH4NO3.

Thirty grams of lead oxide and fifteen grams of ammonia react completely to produce solid lead, nitrogen gas, and liquid water. What will be approximate mass of all three products? 10 g 15 g 45 g 450 g

The smallest unit of charge is - 1.6*10-19 C, which is the charge in coulombs of a single electron. Robert Millikan was able to measure the charge on small droplets of oil by suspending them between a pair of electrically charged plates.