Sun, earth and moon.?

The Earth is almost four times the diameter of the Moon, so the Moon could never eclipse the Earth. Here is a picture of the Earth and Moon taken from Mercury.

From Sun Earth & Moon are about the same mean distance.

Moon is 3/11 ͭ ͪ (27%) in diameter of Earth, covering a disc area that is about 3/40 ͭ ͪ (in fact ⅙ ͭ ͪ is the ratio of masses).

With that Thew shadow of M oon on Earth is a moving dark dot. Earth shadow on Mon is much bigger embracing the whole of Moon .

Quantum is correct.

The Sun and Moon appear to be about the same size from Earth because the Moon, though much smaller than the Sun, is much closer to us than is the Sun.

Both Earth and Moon are approximately the same distance from the Sun, so basically standing on the Sun they would appear to have the same relative size that they actually do have.

For the Moon to look about the same size as the Earth, you would have to be significantly closer to the Moon than to the Earth - about 4 times closer.

No. The moon is about 1/6 th size of the earth, and, at some 90,000,000 miles, it would appear far smaller than the earth. Viewing the earth-moon pairing from the un, we would see th moon transit the earth, much the same way as we see Venus and Mercury transit the sun.

Nope... from the sun, the Earth is going to look about 4 times larger. The moon would only cover about 1/4 of the Earth's surface if it were in front of the Earth...

no, because during solar eclipse shadow of moon covers small area of earth and sun still shine on the rest of the area of earth. so earth is visible from sun even when there's moon in a middle.

Based on size and albedo, the full earth is actually about 40 times brighter than the full moon.

No.