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! :)

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;

they had the law tat factories that produces smoke cannot be built near residential buildings.

building of proper sewage system was done to ensure that the waste is carried away from the humans so that they do not get diseases from it.

also they built water systems to provide water in those areas which are drought prone.