A reaction which needs to gives off energy to complete the chemical reactions is called an

A) adiabatic reaction.

B) oxidation reaction.

C) exothermic reaction.

D) endothermic reaction.

It is safe to stand on the top step of a ladder provided it is braced properly. A) True B) False

What is an element? A. a material that is shiny and usually hard and strong B. a substance made of just one kind of atom that cannot be broken down into something simpler C. a substance made up of hydrogen and one other kind of atom D.

Calcium carbonate () is 34.5% Ca by mass. In a 418 g sample of, how many grams of calcium are present?

Why do different elements have different colored flames when they are heated?

Some ICI is added to an empty flask. How do the reaction rates change as the system approaches equilibrium? A. Foward rate increases, reverse rate increases B. Fwd rate increases, reverse rate decreases C.

Which answer accurately describes the difference between speed and velocity? Read each answer choice carefully. Question 4 options: A. If speed is constant, then velocity is also constant. B. Speed requires direction.

Least reactive element of period 3

A chemical formula shows the kind and number of Atoms that form a what? compound, mixture, solution, or suspension

What gas was used as a deadly posiosn in world war 1?

Four moles of hydrogen chloride (HCl) gas react with one mole of oxygen (O2) gas to produce two moles of chlorine gas (Cl2) and two moles of water gas (H2O).