Answer:
2-
Explanation:
For an element to be stable, it must follow the octet rule: an atom will gain, lose or share electrons until its valence shell is complete with 8 electrons.
An element with the valence electron configuration ns²np⁴ has 6 (2+4) electrons in its valence shell. Thus, in order to fulfill the octet, it will gain 2 electrons. As a consequence, it will form an anion with charge 2-.
Answer:
36.09% is the mass percent composition of calcium in calcium chloride
Explanation:
Mass percent is defined as one hundred times the ratio between the mass of a compound (In this case, Calcium), and the total mass of the sample:
<em>Mass Percent = Mass compound / Total mass of the sample × 100</em>
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Computing the values of the problem:
Mass Percent = 0.690g / 1.912g * 100
Mass percent =
<h3>36.09% is the mass percent composition of calcium in calcium chloride</h3>
Answer:
The nuclear decay of radioactive elements is a process that is a useful tool for determining the absolute age of fossils and rocks. It is used as a clock, in which daughter elements or isotopes converted from parent isotopes by decaying at a particular time.
Radioactive decay rates are constant and do not change over time. It is measured in half-life. A half-life is a time it takes half of a parent isotope to decay and converted into a stable daughter isotope. How many parent isotopes and daughter isotopes present in the fossil or their abundance can help in determining the age of fossil or rock.
Mass = Density × Volume
= 30.0 mg / mL × 375 mL
= 11250 mg
= 11.25 g
∴ the total mass of insulin in the bottle is 11.25 g (11250 mg)
