What are the four observations that confirm that a chemical reaction is happening?

1.) Precipitate is formed 
2.) Odour 
3.) Heat is emitted ( change in temperature) 
4.) Formation of a Gas

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