Answer:
Efficiency of the machine = 75%
Explanation:
Given:
Input work = 8,000 J
Output work = 6,000 J
Find:
Efficiency of the machine
Computation:
Efficiency of the machine = [Output work / Input work]100
Efficiency of the machine = [6,000 / 8,000]100
Efficiency of the machine = 75%
B. convection is the answer
Answer:
False
Explanation:
Geothermal pumps can be used for cooling and heating.
Answer: An atom valence electron shell determines its chemical reactivity.
Explanation:
An atom's valence electron shell determines its chemical reactivity. The amount of electrons in the outermost shell of an atom is its valence electron and it determines how reactive the atom is.
The reactivity of an atom depends on the number of electrons in its outermost shell. Atoms that has their outermost electrons full e.g noble gases like argon, krypton etc are unreactive because there is no room for the atom to donate or accept any electron.
Elements like sodium and chlorine are reactive because they possesses 1 and 7 electrons in their outermost shell respectively as such they can donate and accept electrons making them reactive elements.
