Mv + mv = 2mv providing each momentum is in the same direction.
1/2 mv^2 + 1/2 mv^2 = mv^2
Rubber. The other three are metals, and therefore good conductors.
Answer:
lithium
Explanation:
A lithium atom contains 3 protons in its nucleus irrespective of the number of neutrons or electrons. Notice that because the lithium atom always has 3 protons, the atomic number for lithium is always 3. The mass number, however, is 6 in the isotope with 3 neutrons, and 7 in the isotope with 4 neutrons.
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