For which of the following reactions are both reactants and products likely to be found when the reaction appears to be complete? Explain.

Mg+O2⇒2MgO

HF + H2O⇆H30+F

Element X is a solid that is brittle, lacks luster, and has six valence electrons. In which group on the Periodic Table would element X be found? (1) 1 (3) 15 (2) 2 (4) 16

A car driving at 105 km/h. what is the speed in mi/min? (1 mi = 1.61 km)

Avogadro argued that equal volumes of different gases collected under similar circumstances contain the same number of particles. He found that the volume is directly proportional to moles of gas when the pressure and volume remain constant.

The pile of ash left after a fire burns out demonstrates what concept? A. Original materials remain after a physical change. B. A chemical change forms new substances. C. Physical properties are never stable. D. Fire recycles most substances.

Why are some rocks more easily weathered than other rocks

An atom has 10 protons, ten neurons and ten electrons. What is the mass of that atom in u unit?

What is the total energy change for the following reaction: CO + H2O - > CO2 + H2?

Planet one two elements are?

Which substance can be decomposed by chemical means? (1) tungsten (3) krypton (2) antimony (4) methane

Chemical equations are used to model A. chemical reactions. B. rates of reactions. C. molecular structures. D. physical changes.