Answer:
38
Explanation:
Symbol: Sr
Atomic mass: 87.62 u
Electrons per shell: 2,8,18,8,2
Atomic number: 38
Electron configuration: [Kr] 5s2
Van der Waals radius: 255 pm
Valence electrons: two
When oxygen is found is peroxide, it has an oxidation number of -1.
The chemical formula of hydrogen peroxide is H2O2. We know that hydrogen always has +1 oxidation state until it forms metal hydrides. So in H2O2, the oxidation state ofhydrogen is +1.
Now, let oxidation state of oxygen be x. So,
2 * (+1) + 2*x = 0
2 + 2x = 0
2x = -2
x = -2 / 2
x = -1
Hence, the oxidation number of oxygen in peroxides is -1
The solution would be like this for this specific problem:
<span>Given:
</span>66.0 g of carbon monoxide
reaction 2 C + O2 → 2 CO
<span>mol e= mass / molar mass <span>
<span>mole of 2CO = 66.0g / (12.011 15.999)g / mol </span>
mole of 2CO = 2.36 (CO and C has a 1:1 mole ratio)
mole of 2CO = 2.36 -> mole of 1 CO = 2.36 / 2 = 1.18
<span>We got 2 moles of C, thus 1.18 x 2 = 2.36
So, we 2.36 </span>moles of carbon are needed to produce 66.0 g of carbon monoxide in the </span>reaction
2 C + O2 → 2 CO.</span>
<span>To add, Carbon nonmetallic
and tetravalent, thus, making four electrons available to form covalent
chemical bonds. </span>