Which branch of science provide the proof that earth is approximately 4.6 billion years old

Earth Science
Can also be considered as a branch of planetary science.

Hey how did you manage to type such a big lab report

If a hydrogen atom is neutral, it must also have  one electron. an oxygen atom (o) has an atomic number of eight (8). this means a neutral oxygen atom has eight protons and eight electrons. the element actium (ac) has an atomic number of 89, so it has 89 protons and 89 electrons in a neutral atom