The isotopes are elements with the same number of protons but different number of neutrons.
Boron atomic number is 5. That is the number of protons.
The natural occurring isotopes of boron contain 5 or 6 neutrons. Other, non stable isotopes, contain from 1 to 16 neutrons.
On the second shell there are two individual subshells:
The "s" subshell has only 1 orbital with max. two electrons spinning around; and the so-called "p" subshell has 3 orbitals with max. 6 electrons (2 on each!)
In total, there are four orbitals with 8 revolving electrons on the second shell.
Hope could help :)
Answer:
101.63° C
Explanation:
Volume expansivity γa = γr - γ g = 18 × 10⁻⁵ - 2.0 × 10⁻⁵ = 16 × 10⁻⁵ /K
v₂ - v₁ / v₁θ = 16 × 10⁻⁵ /K
(500 - 492 ) mL / (492 × 16 × 10⁻⁵) = θ
θ = 101.63° C
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