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.
Answer:
Valence electrons are negatively charged particles located in the outermost shell of atoms that can be transferred or shared with other atoms. Valence electrons are important in chemistry because the number of valence electrons in a particular atom can be used to determine how the atom will react chemically with other atoms.
Answer: gas vibrate and move freely at high speeds.
Explanation: liquid vibrate, move about, and slide past each other. solid vibrate (jiggle) but generally do not move from place to place.
Answer:
C. It is reactive because it must gain two electrons to have a full outermost energy level.
Step-by-step explanation:
The electron configuration of this element ends in 2s²2p⁴.
A filled energy level would end in 2s²2p⁶.
The element will be reactive, because it must gain electrons to have a full energy level, and it needs two more electrons to do this.