To check whether an equation is balanced, .

a. add the number of reactants to the number of products
b. make sure the masses of the reactants and products are the same
c. count the number of each type of atom on each side
d. check to see if the reaction is endothermic or exothermic

Energy is usually only shown with the products in an equation for .

a. an endothermic reaction
b. a synthesis reaction
c. an exothermic reaction
d. activation energy

Needthe meter is the standard unit for: 1) height 2) length 3) weight 4) mass

The atomic radius of sodium is 186 pm and of chlorine is 100 pm. the ionic radius for na+ is 102 pm and for cl– is 181 pm. in going from na to cl in period 3, why does the atomic radius decrease while the ionic radius increases? a. the inner electrons in the sodium cation shield its valence electrons more effectively than the inner electrons in the chloride anion do. b. the inner electrons shield the valence electrons more effectively in the chlorine atom than in the chloride anion. c. the outermost electrons in chloride experience a smaller effective nuclear charge than those in the sodium cation do. d. the outermost electrons in chloride experience a larger effective nuclear charge than those in the sodium cation do. e. monatomic ions are bigger than the atoms from which they are formed.

Compare and contrast refraction of light and sound will give brainliest