Answer:
5.17.
Explanation:
<em>∵ [H₃O⁺][OH⁻] = 10⁻¹⁴.
</em>
[OH⁻] = 1.5 x 10⁻⁹ M.
∴ [H₃O⁺] = 10⁻¹⁴/[OH⁻] = 10⁻¹⁴/(1.5 x 10⁻⁹ M) = 6.66 × 10⁻⁶ M.
∵ pH = - log[H₃O⁺]
<em>∴ pH = - log(6.66 × 10⁻⁶ M) = 5.17.
</em>
<h2>Answer:</h2><h3>Part 1:</h3>
Location the element zinc (Zn) on the periodic table:
- Group number : 12
- Period number : 4
- Block : d block
- Element : Transition elements.
<h3>Part 2:</h3>
Protons in an atom of Zn: 30
<h3>Part 3:</h3>
Electrons in a Zn atom: 30
<h3>Part 4 :</h3>
Neutron in an atom of Zn: 35
<h3 />
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<h3>1. <u>Answer;</u></h3>
a. the strong nuclear force is much greater than the electric force.
<h3><u>Explanation</u>;</h3>
- <em><u>For an atom to be stable it means it has enough amount of binding energy to hold its nucleus together permanently. </u></em>
- Therefore, <em><u>an unstable atom lacks enough amount of binding energy to hold its nucleus permanently and thus undergoes decay to achieve stability. Unstable atoms are therefore referred to being radioactive.</u></em>
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Small atoms are stable; <u>this is because they have equal number of protons and neutrons and thus the protons and neutrons fill up energy levels while maximizing the strong force binding the nucleus together. </u>
<h3>9.<u> Answer;</u></h3>
b. change into a different element altogether.
Uranium-238 undergoes alpha decay. Therefore, uranium-238 will <em><u>change into a different element altogether</u></em>.
<h3><u>
Explanation;</u></h3>
- Unstable atoms undergo radioactive decay in order to achieve stability of their nucleus.
- <em><u>Uranium-238 is an example of such atom, which may undergo decay to achieve stability.</u></em>
- <em><u>Alpha decay is one of the types of decays,</u></em> others being beta decay and gamma decay. <em><u>In alpha decay the radioactive isotope undergoes decay such that its mass number is decreased by four and its atomic number is decreased by two.</u></em>
-
Therefore, <em><u>Uranium-238 undergoes alpha decay to form a different element whose mass number is 234 and atomic number is 90, known as thorium-234. </u></em>
Answer:
# 5
Explanation:
The question describes silver being "poured" into a mold and cools to become a solid bar. This is the phase of liquid to solid. When a element cools down below it's freezing points to become a solid.
<u>Liquid to Solid Definition:</u>
Freezing, or solidification, is a phase transition in which a liquid turns into a solid when its temperature is lowered to or below its freezing point. All known liquids, except helium, freeze when the temperature is low enough.