Multiple choice

1. An isotope is an atom of an element that varies in mass number due to variation in the number of: (Points: 5) 
atoms. 
protons. 
neutrons. 
electrons. 

2. A covalent bond is: (Points: 5) 
the attraction that one atom has for another atom. 
the attraction between two atoms, formed by the sharing of electrons. 
formed between the positive charge of a hydrogen atom in one molecule and the negative charge of anitrogen atom in another nearby molecule. 
the attraction between a positive ion and a negative ion. 

3. Solutions are always comprised of: (Points: 5) 
solvents and solute. 
liquids and solids. 
water and salts. 
compounds and ions. 

4. Which of the following is a chemical reaction that is also known as digestion? (Points: 5) 
Phosphorylation 
Dehydration synthesis 
Acid-base 
Hydrolysis