The periodic table is grouped by the properties of each element. They are also arranged in the order of their atomic mass. Different rows of elements are called periods. If elements lie in the same column, they are in the same group. It is helpful to us today because it helps us gain new information on the properties and the world around us. We would not have a true understanding of Chemistry if it were not for the period table.
3. Cl₂ + 2KI --> 2KCl + I₂
Cl = 2 Cl = 2
K = 2 K = 2
I = 2 I = 2
4. 2NaCl --> 2Na + Cl₂
Na = 2 Na = 2
Cl = 2 Cl = 2
5. 4Na + O₂ --> 2Na₂O
Na = 4 Na = 4
O = 2 O = 2
6. 2Na + 2HCl --> H₂ + 2NaCl
Na = 2 Na = 2
H = 2 H = 2
Cl = 2 Cl = 2
7. 2K + Cl₂ --> 2KCl
K = 2 K = 2
Cl = 2 Cl = 2
A gas, HCl is a simple covalent structure which has little intermolecular attraction so this is easily overcome (pretty much the same reasons as the other one I just answered for you)
The correct answer should be D. can be real or virtual depending on the object's placement
Depending on the position on the mirror, it can be determined whether the object is real or virtual.