Explanation:
Beryllium is a group 2 element and its atomic number is 4. Electronic configuration of beryllium is 
.
Since, a beryllium contains two valence electrons so, in order to attain stability it will readily lose its 2 valence electrons.
Therefore, a beryllium atom upon losing two valence electrons will acquire a +2 charge.
Thus, we can conclude that the net ion charge of Beryllium is +2.
I believe the answer is a because 2 times 12 is 24. Hope this helped
<span>Friction creates heat which in turn can lead to deviations from the original size and shape of a part.
</span>
The formula of Iron(III) oxide is Fe2O3
In order to calculate the mass of iron in a given sample of iron(III) oxide, we must first know the mass percentage of iron in iron(III) oxide. This is calculated by:
[mass of iron in one mole of iron(III) oxide/ mass of one mole of iron(III) oxide] * 100
= [(moles of iron * Mr of iron) / (moles of Iron * Mr of Iron + moles of Oxygen * Mr of Oxygen)] * 100
= [(2 * 56) / (2 * 56 + 3 * 16)] * 100
= (112 / 160) * 100
= 70%
Thus, in a 100g sample, the weight of iron will be:
100 * 70%
= 70 grams
