When the products of a reaction have more energy than the reactants:

the reaction is exothermic

the reaction is endothermic

the reactants gave up energy

the H is positive

Why has Earth's climate changed so rapidly in recent years? (a) The sun has gotten much hotter. (b) People are eating too many plants. (c) People are burning too many fossil fuels. (D) The Earth is rotating too slowly to cool off effectively

What is true when an element is oxidized?

The gas in the ozonosphere that absorbs most of the ultraviolet rays from the sun is the___. Oxygen Nitrogen Ozone. Carbon dioxide.

4. What do the numbers in Carbon-12 and Carbon-14 represent?!

Is the following true or false? The energy stored in fuels can be used to generate electricity.

What are the carbon (C) and oxygen (O) in carbon dioxide (CO2) ? (select all that apply) A) Atoms B) Compounds C) Elements D) Molecules

What does the chemical formula C3H2O, tell about a molecule of the compound it represents?

No two different elements will have the atomic number.-

Which two scenarios illustrate the relationship between pressure and volume as described by Boyle's law? 1. The pressure in a closed bottle decreases when the bottle is squeezed. 2.

0.210 mol of octane is allowed to react with 0.760 mol of oxygen. which is the limiting reactant?