Answer:
A
Explanation:
The group number of an element is equal to the number of electrons the outermost shell (or highest energy level) contains
Answer is: quark.
Quark is a type of elementary particle and a fundamental constituent of matter.
Quarks form composite hadrons (protons and neutrons). Protons and neutrons are in the nucleus of an atom.
Hadrons include baryons (protons and neutrons) and mesons.
There are six types of quarks: up, down, strange, charm, bottom, and top.
It is very important<span> to know the shape of a molecule if one is to understand its reactions. It is also desirable to have a simple method to predict the geometries of compounds. For main group compounds, the </span>VSEPR<span> method is such a predictive tool and unsurpassed as a handy predictive method.</span>
