How long has there been life on earth?

a. 4.6 billion years,

b. 3.7 billion years,

c. 65 million years,

d. 3 million years

In the vertical columns of the periodic table, as the atomic numbers increase: a. the number of electron shells increases. b. the ionization energies increase. c. the number of electrons in the valence shell increases. d.

An atom with an atomic number of 18 will have how many electrons in its innermost orbit

Photosynthesis is vital for maintaining levels of atmospheric oxygen. true or falcetrue - photosynthesis is vital for maintaining levels of atmospheric oxygen.

Consider the structure of the phosphonium ylide formed by treatment of the following haloalkane with triphenylphosphine followed by butyllithium. Draw the structure of the alkene formed by reaction of this phosphonium ylide with acetone.

Which bond or interaction would be difficult to disrupt when compounds are put into water? which bond or interaction would be difficult to disrupt when compounds are put into water?

How does oxygen obey the octet rule when reacting to form compounds? A) It gains electrons. B) It gives up electrons. C) It does not change its number of electrons. D) Oxygen does not obey the octet rule.

Which equation obeys the law of conservation of mass? A. 2Fe+3O2 - -> 2Fe2O3 B. 4Fe+O2--> 2Fe2O3 C. Fe+O2--> Fe2O2 D. 4Fe+3O2--> 2Fe2O3

Why do airbags fill evenly with gases?

In which of the following reactions will Kc = Kp? In which of the following reactions will Kc = Kp? (A) SO3 (g) + NO (g) ↔ SO2 (g) + NO2 (g) (B) 2 N2 (g) + O2 (g) ↔ 2 N2O (g) (C) 4 NH3 (g) + 3 O2 (g) ↔ 2 N2 (g) + 6 H2O (g) (D) 2 SO2 (g) + O2 (g) ↔ 2

Which tool is most suitable for a chemist to measure the mass of a liquid