C) Occurs when chemical reactions dissolve or change the minerals in rocks...... Hope it helps, have a nice day :)
Answer:
Sample A - Mixture
Sample B - (can't decide)
Explanation:
We know a mixture as a sample that is made up of two or more substances. Based on the results from the experiment conducted on sample A, the sample is a mixture. Each colour that appeared on the paper represents one of the components of the mixture.
For Sample B, at a particular sharp temperature, the crystals begin to appear. That temperature at which the first crystal appears is actually the melting point of the solid. We were also told that only half of the clear liquid was crystallized meaning that other substances may still be contained in the remaining liquid. Crystallization is a separation technique that depends on differences in melting points of substances. We can't decide if the sample is pure because we have no further information about what happened to the remaining liquid. That would have told us if the liquid remaining was just the solvent used to dissolve B which could have also been evaporated to leave only the pure sample.
Answer:
This is
1 mole = 18 gram = 6×10^23 molecules
1 gram = ?
1 gram= 18/6×10^23 atoms
1 gram =3×10^-23 atoms
Democritus (460-370 BC) was a Greek philosopher who theorized that all matter could be reduced to particles that could not be divided, which he described as “atomos.”
John Dalton (1766-1844) Proposed the atomic theory.
Answer:
c.
Explanation:
It prevents consumers from purchasing unnecessary goods.
