Elements 1 and 3 are used to make the most common substance in the body. what are these elements?

a. nitrogren & phosphorus
b. oxygen & hydrogen
c. hydrogen & helium
d. oxygen & sulfur

The right answer is B. Oxygen & Hydrogen.

The abundance an elements is the measure of their proportion in a given environment. Their abundance can be measured by mass, molar, atomic or volume fraction.

Hydrogen is the most abundant element in organisms or throughout the Milky Way. It composes water and organic matter. Oxygen comes in third place since it is present in the majority of organic components.

1. (1.2kw)x(15/60hours) = .3kwh --> a

2. (5kw)x(90/60hours)x(8cents/kwh) = $0.60 --> d

3. microwave --> 1200 watts = (1.2kw)x(6/60hours) = .12kwh

coffee-maker --> 900 watts = (.9kw)x(10/60hours) = .15kwh

therefore, it requires more energy for the coffee-maker to do the same amount of work.

so the answer is a.