Answer:
Explanation:
The question is asking to write the <em>isotopic symbol </em>of the form 
for the <em>sodium isotope with 13 neutrons</em>.
In general, the isotopic symbol in the given form shows:
- The element's chemical symbol: X
- A: mass number of the isotope, written as a superscript to the left of the element's simbol, and
A = number of protons + number of neutrons
- Z: atomic number of the isotope, written as a subscript to the left of the elements's symbol,
Z = number of protons
The atomic symbol of sodium is Na.
The atomic number, or number of protons, is the same for every isotope of the element, and you can find it in any periodic table. Tha atomic number of sodium is 11. Thus:
The mass number is the number of protons plus neutrons, hence:
Now you can write the isotope symbol for the sodium isotope with 13 neutrons:
Answer:
- <u><em>The bag with no sunscreen held the most vibrant beads.</em></u>
Explanation:
<em>SPF</em> is the Sun Protection Factor. It indicates how long a person can stay out in the sun before his skin start burning. It is a factor that is multiplied by 15 minutes. SPF 30 means 30 times 15 = 450 minutes. SPF 70 means 70 times 15 = 1,050 minutes.
Thus, the bag covered in <em>SPF 30</em> <em>sunscreen</em> will raise its temperature faster than the bag covered in <em>SPF 70 </em>sunscreen. And the bag with <em>no sunscreen </em>will raise its temperature faster than the other two.
The higher the temperature the more vibrant the particles that consititute the substances, thus, you conclude that the bag that held the most vibrant beads is the bag with no sunscreen.
Remember that the temperature is a measure of the kinetic energy:. The relation is: the higher the temperature the higher the kinetic energy.
Therefore, the more the particles vibrate, the higher the kinetic energy and the higher the temperature.
<span>Which element listed below is considered an alkaline earth metal?
</span>B) Magnesium
Answer:
hydrogen and oxygen make up water molecules
Atoms will either try to lose or gain electrons in order to have eight electrons in the outermost shell (excluding hydrogen, which only needs 2 for a full outer shell)
