Answer:
A molecule is a group of two or more atoms held together by chemical bonds. A compound is a substance which is formed by two or more different types of elements which are united chemically in a fixed proportion. All molecules are not compounds.
Good luck !
Answer: HCl
Explanation:
calcium carbonate dissolves in HCl acid producing CO 2 gas. It will not dissolve in pure water. The Ksp for calcium carbonate in water is 3.4 x 10-9 moldm-3 which is very low. What takes place here is actually a chemical reaction:
CaCO 3 (s) + 2HCl(aq) → CaCl 2 (aq) + H 2CO 3(aq)
This reaction accounts for the solubility of the Calcium carbonate in HCl and not in pure water.
Mitosis makes new cells and replaces the cells that are old, lost or damaged
Answer:
The answer to your question is
1.- 1.686 x 10²⁴ atoms
2.- 0.25 moles
Explanation:
1.-
1 mol ---------------- 6.023 x 10²³ atoms
2.8 moles ---------- x
x = (2.8 x 6.023 x 10²³) / 1
x = 1.686 x 10²⁴ atoms
2.- 1 mol ------------------ 6.023 x 10 ²³ molecules
x moles ------------- 1.50 x 10²³ molecules
x = (1.50 x 10²³ x 1) / 6.023 x 10²³
x = 0.25 moles
