Okay, to explain this you might have to grab a periodic table.
Do you have one? Good. Look at the most left side of the periodic table. The first group is the largest atoms in the periodic table. If you go to the right of the periodic table, the atoms get progressively smaller and smaller.
Why is this? Don't atoms get more electrons, and so become significantly bigger as they move to the right?
Although atoms do get more electrons as they go to the right, they also get more protons too. Protons pull on electrons and make atoms smaller. Because of this, going from left to right in a periodic table makes the atoms smaller and smaller, since more and more protons are added.
In this scenario, Aluminum is more to the right than Sodium, which means that it has more protons. Because of this, the protons in Aluminum pull more strongly on electrons than sodium, thus making aluminum smaller.
(Just a side note, going down in a periodic table makes the atoms bigger, since new shells are added every time)
Good luck! If you need any help, just ask :))
-T.B.
Answer:
3)alpha decay because alpha particles have two protons and two neutrons
Explanation:
When a radioactive isotope undergoes a decay, a daughter nucleus or nuclei is/are formed. The mass number and atomic number of the daughter nucleus gives us an idea of the nature of radioactive decay that the parent nucleus underwent.
If the daughter mass number of the daughter nucleus is four units less than that of the parent nucleus and the atomic number of the daughter nucleus is two units less than that of the parent, then such a decay is an alpha decay.
An alpha particle has two protons and two neutrons thus it has a mass number of 4 and an atomic number of two.
P (phosphorous ) = 30.97 g/mol<span> * 2 = 61.94 g/mol.</span>
<span>O ( oxygen ) = </span>16.00 g/mol<span> * 8 = 128.00 g/mol.</span>
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<span>Calcium Phosphate Ca3(PO4)2 = </span>310.18 g/mol<span>. </span>
4Fe + 3O2 -> 2Fe2O3
triple it to get 6 Moles of Fe2O3
12Fe + 9O2 -> 6Fe2O3
so 9 moles of diatomic oxygen are required
Answer:
When it is heated above about 80°C it begins to break down, forming sodium carbonate, water and carbon dioxide. This type of reaction is called a thermal decomposition.
