Please help!
1. In this model of a molecule of ammonia, NH3, how many covalent bonds are represented?

A. 1 covalent bond
B. 2 covalent bonds
C. 3 covalent bonds
D. 4 covalent bonds

10 newton object is placed 3 meters from the fulcrum. at what distance on the other side would you need to place a 15 newton object to balance the lever? show your work!

Newtons view of arrangement of the universe

The average atmospheric pressure on earth is approximated as a function of altitude by the relation patm = 101.325 (1 − 0.02256z)5.256, where patm is the atmospheric pressure in kpa, and z is the altitude in km with z = 0 at sea level. determine the approximate atmospheric pressures at atlanta (z = 306 m), denver (z = 1610 m), mexico city (z = 2309 m), and the top of mount everest (z = 8848 m).