Answer:
magnesium
Explanation:
magnesium is in Group 2, in the periodic table. this means that it has 2 valence electrons. the less valence electrons an element or atom has, the more reactive. Selenium has 6 valence electrons. as a result, Mg is more reactive
It increases across a period and decreases down a group. A good way to remember this is that fluorine is the most electronegative atom, and it's to the top right of the table.
<h3><u>Answer;</u></h3>
3.64 moles
<h3><u>Explanation;</u></h3>
From the equation;
2Cu + O2 → 2CuO
Mole ratio of Cu : CuO = 2: 2 equivalent to 1: 1
Moles of CuO = 3.64 Moles
Therefore;
moles of Cu will be ;
3.64 × 1 = 3.64 moles
Moles of Cu = <u>3.64 moles </u>
Using the relative atomic weights of both copper and sulfur ie copper = 63.55 and sulfur is 32.06 so 63.55+32.06=95.56 total mass and so of this, copper = 63.55/95.56=66.4%. So to get 10 grams of copper, use the formula 10g=66.4%xCuS so CuS=10/0.664=15.06 grams of CuS.
