When a cup is placed on a table, which force prevents the cup from falling to the ground? O A gravitational force OB. normal force Ос. resistance force OD. tension force

How many atoms are in 1.4 mil of phosphorus trifluoride (pf3)

Iknow #2 is d. i just need to know why

Zoe is investigating the composition of substance a, an unknown substance. using chemical processes, she analyzes substance a and determines it is composed of sodium, oxygen, and hydrogen atoms in a ratio of 1 : 1 : 1. what is substance a? a. a compound b. an element c. a heterogeneous mixture d. a homogeneous mixture