Answer:
It is valid because his experiment had clear variables.
Explanation:
He had clear variables and did everyhting the same for both plants, even though he had calcium in one and not in the other, which gives him a true and good result.
Chemical science deals with mater like compound mater
Answer:
it is the moisture in the air
Explanation:
if we buy a dehumidephire we see that it collets water from the air
Answer:
3.0 mol.
Explanation:
<em>Molaity (m) is defined as the no. of moles of solute per kg of solvent.</em>
<em />
<em>m = (no. of moles of solute Ca(NO₃)₂)/(kg of solvent).</em>
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<em>∴ no. of moles of solute Ca(NO₃)₂ = (m)(kg of solvent)</em> = (3.0 m)(1.0 kg) = <em>3.0 mol.</em>