Answer:
4- radioactive isotopes
Explanation:
I don't remember exactly but this question was on the regents
Atomic mass=no of neutron+no of electron
Atomic mass=25+30
Atomic mass=55
1) 2
2) 2
3) there are 2 atoms of hydrogen and 1 atom of oxygen, altogether is 3
4) subscript tells how many atoms of each element are present in the molecule
5) No, it is not balanced because the oxygen atom is not equal on both sides of the reactants and products. This wouldn’t be considered balanced as there are two oxygen atoms in the reactants section and only one oxygen on the products section.
It is:
2 H2 + O2 -> 2 H2O
Answer: B) 2 (as indicated by electron distribution shown), but taking into account the real properties of this element, 4,7,8 also occur (see below).
Explanation:
This is the electron complement/atomic number of ruthenium, which actually has the structure [Kr] 5s1 4d7
Nevertheless, Ru does not form Ru(I) compounds and few Ru(II) compounds (RuCl2, RuBr2, RuI2). It also forms Ru(III)Cl3 and a larger number of Ru(IV) compounds, e.g. RuO2, RuS2. It also forms RuO4
