Which best describes an acid? (F)
a soapy substance that is nonreactive
with metals
(G)
a neutral substance made of oppositely
charged particles
(H) a caustic substance that has a high
number on the pH scale
(I) a sour liquid that forms gas bubbles
when mixed with copper

H) a caustic substance that has a high

number on the pH scale

Explanation:

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.