Answer:
B. 138
Explanation:
Based on isotope notation:
For the atom A, the mass number, X, is the sum of neutrons and protons and
n is the number of protons = Atomic number.
The number of protons depends of the nature of the atom. For example, Carbon has 12 protons, hydrogen 1 and <em>Radium has 88 protons.</em>
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The radium-226 means the mass number is 226. Thus, number of neutrons are:
Mass number - Atomic number
226 - 88 = 138
Right answer is:
<h3>B. 138
</h3>
Hello!
Use the equation d = s · t where:
s = speed
t = time
d = distance
Plug in the given distance and speed:
20 = 12 ·t
Divide both side by 12 to isolate for t:
20/12 = t
Simplify:
5 / 3 = t
Therefore, it took 5/3 hours to bike. We can convert this to minutes if necessary:
5/3 · 60 min (in one hour) = (60 · 5) / 3 = 100 min.
Electrons hold a negative charge, and anion refers to a negatively charged atom.
The answer is anion. Here's a way to help remember:
Cats have paws, and cations are "paws"itive (positive).
