Answer:
True
Explanation:
The physical and chemical properties of a substance depend on the nature of intermolecular forces between its molecules. For instance, water has a high boiling point because of hydrogen bonding between water molecules. Liquid water is denser than ice because of the difference in the nature of hydrogen bonding in liquid water and ice.
Answer:
The ionic compound NaCl has a Face Centered Cubic unit cell
The site for atoms are Face, center and Edges corner.
Effective number of atoms
Na+
1centers + 12edges x
= 4 Na+
Cl-
6face x
+ 
x8 corners = 4Cl-
This is just one unit cell effective atom, there are thousand's of such unit cells are combined to form one such structure of NaCl. The real formula of NaCl is Na4Cl4 but for simplicity we use empirical formula that is NaCl.
Due to the ability of ionized atmospheric gases to refract high frequency (HF, or shortwave) radio waves, the ionosphere can reflect radio waves directed into the sky back toward the Earth. Radio waves directed at an angle into the sky can return to Earth beyond the horizon.
I hope this helps !
The arrow can also mean yields.
If you will understand the unified structure of atoms, you will also understand what are the siginificance of the protons, electrons and neutrons. so when you are given an unfamiliar element, if you know the number of protons or electron then you will know its atomic number, and if you know the number of protons and neutrons then you will know the mass of the element
