Answer:
Cells are the smallest living unit of an organism
The statement that is true is that B. Atoms always remain intact during chemical reactions.
Atoms simply mean the <u>basic units of matter.</u> They're the defining structure of an element. Atom is also known as the smallest unit of matter.
It should be noted that atoms always remain intact during chemical reactions. They cannot be added and removed when there are <em>chemical reactions.</em>
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The second option only.
<h3>Explanation</h3>
A base neutralizes an acid when the two reacts to produce water and a salt.
Sulfuric acid H₂SO₄ is the acid here. There are more than one classes of bases that can neutralize H₂SO₄. Among the options, there are:
Metal hydroxides
Metal hydroxides react with sulfuric acid to produce water and the sulfate salt of the metal.
.
The formula for calcium sulfate 
in option A is spelled incorrectly. Why? The charge on each calcium 
is +2. The charge on each sulfate ion 
is -2. Unlike 
ions, it takes only one ion to balance the charge on each ion. As a result, and ions in calcium sulfate exist on a 1:1 ratio.
.
Ammonia, NH₃
Ammonia NH₃ can also act as a base and neutralize acids. NH₃ exists as NH₄OH in water:
.
The ion 
acts like a metal cation. Similarly to the metal hydroxides, NH₃ (or NH₄OH) neutralizes H₂SO₄ to produce water and a salt:
.
The formula of the salt (NH₄)₂SO₄ in the fourth option spelled the ammonium ion incorrectly.
As part of the salt (NH₄)₂SO₄, the ammonium ion NH₄⁺ is one of the products of this reaction and can't neutralize H₂SO₄ any further.
<span>When a large number of atoms of the same isotope are observed they will have a statistically consistent half life.
</span>An unstable nucleus contains a near excessive number of RNA chemical can spontaneously break apart into one or more nuclei all with a lighter state. #believe
