We can define atomic mass the total of number of protons and number of neutrons in an atom or isotope.
<span>So when an isotope of yttrium has 39 protons and 59 neutrons, its atomic mass is equal to;
number of protons + number of neutrons = 39 + 59 = 98</span>
Answer:
in a chemical reaction, the mass of the products will always be equal to the mass of the reactants.
Explanation:
Answer:
Atom is a the smallest particle of a chemical element that can exist.
Molecules is a a group of atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction.
Particles is a minute portion of matter.
A particle can be a single atom or a molecule ( a group of atoms held together by chemical bonds).
Rubidium is an element that belongs to Group 1. As such it will have physical properties similar to the other Group 1 elements. Rubidium is below
Potassium in the periodic table but above
Cesium. As such it would be most like one of those two elements.
Answer:
I think the answer should be B. Number of valence electrons
