Answer:
One: <u>Selenium</u> is Paramagnetic
Explanation:
Those compounds which have unpaired electrons are attracted towards magnet. This property is called as paramagnetism. Lets see why remaining are not paramagnetic.
Electronic configuration of Scandium;
Sc = 21 = 1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d¹
Sc³⁺ = 1s², 2s², 2p⁶, 3s², 3p⁶
Hence in Sc³⁺ there is no unpaired electron.
Electronic configuration of Bromine;
Br = 35 = 1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d¹⁰, 4p⁵
Br⁻ = 1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d¹⁰, 4p⁶
Hence in Br⁻ there is no unpaired electron.
Electronic configuration of Magnesium;
Mg = 12 = 1s², 2s², 2p⁶, 3s²
Mg²⁺ = 1s², 2s², 2p⁶
Hence in Mg²⁺ there is no unpaired electron.
Electronic configuration of selenium;
Se = 34 = 1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d¹⁰, 4p⁴
Or,
Se = 34 = 1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d¹⁰, 4px², 4py¹, 4pz¹
Hence in Se there are two unpaired electrons hence it is paramagnetic in nature.
If acetone has a density of 0.7857 the mass in grams of point A is 22.4 g and the volume at point B is 8.32 mL.
<h3>What is acetone?</h3>
Acetone is known as a chemical substance that is usually found in the environment but can also be produced artificially. Acetone is a polar organic product that interacts very well with water molecules, generating dipole-dipole relationships.It is colorless with a distinctive smell and taste, we find it in products known as <u>cleaning and personal care products</u>, but we can also use it as a solvent for substances.
Also in the environment in <u>plants, trees and in volcano emissions or in forest fires</u>, it does not become <em>toxic</em> in low doses but if it is exposed to an individual in high doses it can become <em>fatal</em>.
In the statement we can find that acetone has a density of 0.7857 .
Therefore, we can confirm that if acetone has a density of 0.7857 the mass in grams of point A is 22.4 g and the volume at point B is 8.32 mL.
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