â¢ Percentage by mass of each element in a compound â¢ Can be determined from the formula of the compound or by experimental mass analysis of the compound â¢ The percentages may not always total to 100% due to rounding. 100%wholepartPercentage. â¢ Determine the mass of each element in 1 mole of the compound.
The Moon travels around the Earth. The Moon travels around the Earth in a circle called an orbit. How long does it take the Moon to orbit the Earth? The Moon takes about 27 days (27 days, 7 hours, 43 minutes, 11.6 seconds) to go all the way around the Earth and return to its starting position. The Moon's orbit around the Earth is a slightly squashed circle called an ellipse.
The Moon spends the extra 2.2 days catching up because Earth travels about 45 million miles around the Sun during the time the Moon completes one orbit around Earth. At the new Moon phase, the Moon is so close to the Sun in the sky that none of the side facing Earth is illuminated (position 1 in illustration). In other words, the Moon is between Earth and Sun. At first quarter, the half-lit Moon is highest in the sky at sunset, then sets about six hours later (3).