<span>Answer: A) They are isotopes of nitrogen and they contain the same number of protons and electrons but each contains a different number of neutrons - 7 and 8 respectively.
Isotopes are atoms of a chemical element whose nucleus has the same atomic number, Z, but different atomic mass, A. The atomic number corresponds to the number of protons in the atom, therefore the isotopes of an element contain the same number of protons and electrons (atoms have to be neutral particles). The difference in atomic masses arises from the difference in the number of neutrons in the atomic nucleus.
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Answer:
11.1 cm
Explanation:
Let d be the depth upto which box dipped into water.
Volume of water displaced
.12\times .12\times d m^3\\
=.0144d
Weight of water displaced = upthrust
=.0144d\times 10^3\times g\\ [ density of water is 1000kg /m³]
=14.4dg This will act upwards.
Total downward force = 1.2 +.4 = 1.6 g
For equilibrium
1.6g = 14.4 gd
d = .111 m
=11.1 cm.
It will roll .. down the hill .. what else
the first one is octet and the second one is stable
