If snails and crayfish die, what happens to the other species?

There are main groups in the modern periodic table of elements

For each of the following compounds, write the formula then predict whether it would be a strong, weak, or non-electrolyte when placed in di water. for the ionic compounds only, put (s) or (aq) after the forrmula formula strong, weak or non electrolyte? a calcium hydroxide b. silver carbonate c. lead(ii) sulfate d. phosphorus trifluoride e. sodium phosphide f barium sulfate g. strontium acetate h. zinc nitrate

How many atoms or molecules are there in a mole of a substance?