Which of the following molecules are Polar? Select all that apply. Group of answer choices
A. CH3Cl
B. HF
C. O2
D. PF5
E. HCN
F. SeBr6
G. H2S

Which formula can be used to calculate the molar mass of ammonia (nh3)? molar mass of n + molar mass of h 3 × molar mass of n + molar mass of h molar mass of n + 3 × molar mass of h 3 × molar mass of n + 3 × molar mass of h

Which of the following is an example of physical change not a chemical change? a) a log gives off heat and light as it burns. b) a tree stores energy from the sun in its fruit. c) a penny lost in the grass slowly changes color. d) a water pipe freezes and cracks on a cold night.

Consider the four elements above. which one of these elements will combine with oxygen in a 1: 1 ratio?