Answer:
optical (optic is the word used for referring to the eye ie optic nerve)
Explanation:
All the members of a family of elements have the same number of valence electrons and similar chemical properties. The horizontal rows on the periodic table are called periods.
Answer:
2Al + 3H2SO4 → Al2(SO4)3 + 3H2
2Fe + 3Cl2 → 2FeCl3
Explanation:
1. (SO4) 3 you see this 3 it means that 3 must be behind H2SO4. So now it's 3H2SO4.
2. If 3 is now behind one H2, it must be behind the other.
So now it's 3H2.
3. Al2 (SO4) 3 has 2 ahead of Al which means there will be 2Al in the reactants.
1. FeCl3 has 3 ahead of Cl, and Cl2 has 2. Which means that behind FeCl3 goes 2, and behind Cl2 goes 3 so now we have equated all Cl.
2. Since it is now 2FeCl3, we know that there must be 2 in the second Fe. It's 2Fe now.