Answer:
As we have already discussed, reactivity of alkali metals tends to increase as you go down the group. Therefore, sodium is less reactive with water than is potassium, likewise with the alkaline metals; calcium is more reactive than magnesium
The correct answer is 2.99 helium atoms.
I hoped this helped!
Answer:
0.416666667
Explanation:
number of moles= mass of sample ÷ molar mass
=5÷12
=0.41666667
The highest sequence for this shell is the number 2, preceding both the s and p in the diagram. This means that the outermost shell is the second level shell. In this shell, there are 7 electrons, 2 in the 2s orbital and 5 in the 2p orbital.
As a side note (not sure if this is a typo), the electron structure for fluorine begins with a 1s2, not a 1s1.