Question 16

what is chalk considered?

a)an element

b)a colloid

c)a compound

d)a solution

Chalk is a C) Compound.

Element refers to one single substance which is made up of atoms and sub atomic particles namely electron, proton and neutron. A colloid is a blend where one substance of minutely scattered insoluble or solvent particles is suspended all through another substance.

Solution is composed of two components solute and solvent. When elements combine together it leads to the formation of compound. Chalk is considered as compound because, it is a substance formed by fusion of carbon dioxide and calcium hydroxide.

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.