2. When do chemical reactions happen?

O

When matter changes states

O

When water freezes into ice

O

When atoms gain, lose, or share electrons

O

When water boils

Which statement describes the energy changes that occur as bonds are broken and formed during a chemical reaction? 1. Energy is absorbed when bonds are both broken and formed. 2. Energy is released when bonds are both broken and formed. 3.

Both ti and hf behave as though they possess the same number of valence electrons. Which of the subshells in the electron configuration of hf behave as valence orbitals?

What is the smallest unit that makes up matter a alloys b atoms c chemicals d molecules

Which of the following is a step in the conversion of 2.5 hm3 to L? fraction cubed: one cm over ten to the second power m fraction cubed: one hm over ten to the negative 2 power m ten to the negative third power L over 1 mL fraction cubed: one ml

A model to show where lighning is likely to strike

There is inverse relation between pressure and diffusion in liquid phase? •True •False

What do you need in order to do a stoichiometric calculation? (Choose multiple) Balanced Chemical Equation Molar masses of compounds involved The type of reaction taking place Oxidation Numbers

The correct mathematical expression for finding the molar solubility (s) of sn (oh) 2 is:

18. which bond is most polar? H--F H--Cl H--Br H--I

What kind of reaction is ca (s) + h3po4 (aq) ca3 (po4) 2 (s) + h2 (g)