Answer is ₂₀⁴²Ca.<span>
In AZX notation
A<span> - Represents the </span>mass number of atom.
Mass number = number of
protons + number of neutrons.
<span> It is shown at
the </span>above of the left side<span> of the
atom.</span>
<span> Here it is </span>42.
<span> </span>Z - Represents the atomic number.<span>
Atomic number = number of protons.
</span><span>It is shown at the</span> bottom line of the left side of the atom.<span>
</span>Here it is 20.<span>
X - </span>Represents the symbol of the atom.<span>
<span> </span></span>Here</span> X is Ca.<span>
</span>
Explanation:
1st question answer true
2nd question low resistance
hope it helps
Answer:
34.23 g.
M = (no. of moles of solute)/(V of the solution (L)).
From the calculation, the moles of water produced is 18 moles of water.
<h3>What is a decomposition reaction?</h3>
A decomposition reaction is one in which a substance is split up into smaller parts.
We have the reaction; 2 Cr(OH)3(aq) ------------> Cr2O3(s) + 3H2O(l)
From this reaction;
2 moles of Cr(OH)3 produced 3 moles of water
12 moles of Cr(OH)3 will produce;
12 moles * 3 moles / 2moles
= 18 moles of water
Hence, 12 moles of chromium (III) hydroxide produces 18 moles of water.
Learn more about decomposition reaction:brainly.com/question/8009068?
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Answer:
(b) Both have the same number of valence electrons.
Step-by-step explanation:
We find the most striking chemical similarities between two Main Group elements when they are in the same Group of the Periodic Table.
Elements in the same Group have the same number of valence electrons.
(a) is <em>wrong</em>, because elements in the same group have <em>different masses</em>.
(c) is <em>wrong,</em> because atoms with the same number of protons belong to the s<em>ame element</em>.
(d) is wrong, because elements in the same Group must be in .
<em>different Periods.</em>
