Answer:
C
Explanation:
75 mile shallow flat area just off coastlines
Explanation:
Physical changes only change the appearance of a substance, not its chemical composition.
Chemical changes cause a substance to change into an entirely substance with a new chemical formula.
Chemical changes are also known as chemical reactions. The “ingredients” of a reaction are called reactants, and the end results are called products
Valence.
The electrons in the outer shell of an atom are called valence electrons.
Valence electrons determine whether the an element is ready form compounds. These electrons can be gained, lost, or shared in the formation of compounds.
Answer:
7.71x10^23 molecules
Explanation:
Avogadro's # = 6.022x10^23
1.28 mol SiO2 x 6.022x10^23/ 1 mol SiO2 = 7.71x10^23 molecules
