Answer:
The answer to your question is A.
Pure substances can not be broken down into others, so they cannot be molecules
Explanation:
The correct option is B.
Isotopes refers to those chemical compounds which have the same number of protons and electrons but different number of neutrons, so they end up having different mass numbers. The diagram given above is that of beryllium, which has atomic number 4 and it has 2 electrons in its outermost shell. It has four protons [same as the number of electrons] and 5 neutrons. Beryllium 10, which is its isotope has four electrons, four protons and 6 neutrons. To get the number of neutron, remove the number of electrons from the number given in the option, that is, 10 - 4 = 6.
Answer:
2.5% of the earth's fresh water is unavailable: locked up in glaciers, polar ice caps, atmosphere, and soil; highly polluted; or lies too far under the earth's surface to be extracted at an affordable cost.
Explanation:
Answer:
The answer is true
Explanation:
This process is called passive transport or facilitated diffusion, and does not require energy. The solute can move "uphill," from regions of lower to higher concentration. This process is called active transport, and requires some form of chemical energy.
