In order to have a contact force acting on an object, the force
a. must be positive
b. must be negative
c. must be touching the object
d. cannot be touching the object

What happens to the atomic radius when an elctron is lost

The following reaction shows sodium carbonate reacting with calcium hydroxide. na2co3 + ca(oh)2 → naoh + caco3 how many grams of naoh are produced from 20.0 grams of na2co3? (molar mass of na = 22.989 g/mol, c = 12.01 g/mol, o = 15.999 g/mol, ca = 40.078 g/mol, h = 1.008 g/mol) 12.2 grams 15.1 grams 24.4 grams 30.2 grams

Why are pipes bursting in the in extremely cold weather?