If the rainwater is always acidic then its pH must be less than 7. pH is a scale which basically means negative log of [H+] or -log[H+] and the range that it covers is from 0 to 14. A substance can be acidic, basic or neutral based on the pH that it has. If the pH of a substance is less than 7 then it means the substance is acidic, if the pH of the substance is more than 7 then it means that the substance is alkaline while a pH of 7 indicates that the substance is neutral.
When reading questions, be careful not to read too quickly. In this case, fast but inefficient reading will lead us to assume that it is asking about ...
Multiple births can include fraternal or identical multiples ... This can happen if your body releases multiple eggs and ... Are a twin yourself or have twins in your family.