1. The atomic mass of the most common isotope of magnesium is . 2. The element with an atomic number of 4 is .

3. exist in orbitals around the nucleus.

4. Oxygen has protons in the nucleus.

5. An isotope of an element has the same number of protons but a different number of .

I just did this for Penn Foster and the correct answers are:
1. 24
2. beryllium
3. Electrons
4. 8
5. neutrons
Hope this helps someone! :)

explanation:

the fossil record extends back to a dog-like ancestor some 55 million years ago, which gave rise to the first horse-like species 55 to 42 million years ago in the genus eohippus.

question: which statement best describes the different properties of metals?

answer: they are shiny and bend without breaking.

since metals have certain characteristics properties, they include the following: they are ductile, malleable, shiny, hard, lustrous, flexible and they are good conductor of heat and electricity. so therefore, metals are not dull and they are not non-flexible as listed. instead, they are shiny and flexible.

hope this , have a good day. c;

the actual answer was 160934