Answer:
a. BH₃
Explanation:
According to the octet rules, atoms reach stability when are surrounded by eight electrons in their valence shell when they combine to form a chemical compound.
From the options, the only compound in which the central atom does not meet the octet rules is BH₃. The central atom is boron (B), which has 3 electrons in its valence shell. When B is combined with hydrogen (H), 3 electrons from the 3 atoms of H are added. The total amount of electrons is 6, fewer than 8 electrons needed to meet the rule.
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Answer:
Total 5 significant digits.
Explanation:
Significant digits are the numbers that give a meaningful contribution. For example, digit 013 has the 2 significant digits and zero is not a significant digit because digits 1 and 3 give meaningful contribution but digit zero does not value meaningful contribution. Similarly, the 89015 has a total of 5 significant digits and these digits are the 8, 9, 0, 1, and 5.
Answer : Electron P has greater energy difference than the Electron N.
Explanation :
Wavelength range of violet light = 400 - 500 nm
Wavelength range of orange light = 600 - 700 nm
The Planck's equation is,

where,
E = energy of light
c = speed of light
= wavelength of light
According to the Planck's equation, wavelength and energy follow inverse relation. As the wavelength increases, energy decreases.
From the given spectrum, the wavelength of violet light is less. We conclude that When electron P gives violet light on transition it means that energy difference between the energy level was high.
From the given spectrum, the wavelength of orange light is more. We conclude that When electron N gives orange light on transition it means that energy difference between the energy level was low.
So, Electron P which gives violet light on transition has greater energy difference than the Electron N.
Humans.
Humans have mass and take up space. :)
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