1. explain how do scientists
know what moon's crust is
made of?

Whent he people went to the moon they told them what it was

Explanation:

"Like the Earth, the Moon has layers. ... Scientists believe that the mantle of the Moon is largely composed of the minerals olivine, orthopyroxene and clinopyroxene. It's also believed to be more iron-rich than the Earth's mantle. The outermost layer of the Moon is called the crust, which extends down to a depth of 50 km."

Explanation:

radioactive decay occurs in unstable atomic nuclei – that is, ones that don't have enough binding energy to hold

the nucleus together due to an excess of either protons or neutrons.

when [oh-] is 10-5  m, and [h3o+] is 10-9  m, the poh is 5 and ph is 9. again in both cases the sum of ph and poh is 14. however, the hydrogen ion concentration is not always going to be equal to exactly 1 x 10 raised to a negative number. for example, we skipped over the value of 2.0 x 10-7.