Answer:
Physical Change
Explanation:
A solid being crushed into a powder is a physical change because a chemical change is when substances combine to create new substances.
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Answer:So far scientists have not found a way to determine the exact age of the Earth directly from Earth rocks because Earth's oldest rocks have been recycled and destroyed by the process of plate tectonics. If there are any of Earth's primordial rocks left in their original state, they have not yet been found.
Explanation:
Answer:
CaSO₄ (calcium suflate) is the precipitate formed
Explanation:
We can think the reactants:
BeSO₄ → Beryllium sulfate
Ca(OH)₂ → Calcium hydroxide
The reaction is:
Be₂SO₄ + Ca(OH)₂ → CaSO₄ ↓ + Be(OH)₂
We call it as a double-replacement reaction because two ions exchange places from 2 compounds to form two new compounds.
Sulfates can always make precipitate with the elements from group 2, Ca, Ba and Mg.
Hydroxides from group 2 are solubles, so we complete states:
BeSO₄ (aq) + Ca(OH)₂ (aq) → CaSO₄ ↓ (s) + Be(OH)₂ (aq)