Answer:
C) 4.0026 amu
Explanation:
Helium (He) is the 2nd element on the Periodic Table.
It's neutral atom has 2 protons and 2 electrons.
It is in the 1st period and the 18th row.
It is also a Noble gas.
Answer:
Mirages happen when the ground is very hot and the air is cool.
Explanation:
They happen when light passes through two layers of air with different temperatures. The desert sun heats the sand, which in turn heats the air just above it. The hot air bends light rays and reflects the sky.
When you see it from a distance, the different air masses colliding with each other act as a mirror.