it is c. ionic compound just because it says ionic. can't be a crystal since there's no links to an ionic bond connected to crystals (and if it were it'd depend on the elements and the thingy majig itself right) and a covalent bond is an entirely different bond which isn't related to ionic. hope this helped, and i hope you have a good day too! :D
Before we describe the phases of the Moon, let's describe what they're not. Some people mistakenly believe the phases come from Earth's shadow cast on the Moon. Others think that the Moon changes shape due to clouds. These are common misconceptions, but they're not true. Instead, the Moon's phase depends only on its position relative to Earth and the Sun.
The Moon doesn't make its own light, it just reflects the Sun's light as all the planets do. The Sun always illuminates one half of the Moon. Since the Moon is tidally locked, we always see the same side from Earth, but there's no permanent "dark side of the Moon." The Sun lights up different sides of the Moon as it orbits around Earth – it's the fraction of the Moon from which we see reflected sunlight that determines the lunar phase.
Gases take the shape of their container and have no definite volume because they can diffuse indefinitely. Answer C.
Rainbows go in the order of ROYGBIV, which is an acronym for red, orange, yellow, green, blue, indigo, violet.
So, it would start off with red.
If you want to know why it starts off the rainbow, its because red has the longest wavelength, compared to the rest of the colors. (sorry I'm rambling, I got excited)
Hope this helps.
Answer:
I'm assuming atmospheric pressure, since it says she is measuring pressure exerted my atmospheric gases
