Ammonia is the compound NH3
Answer:
Modern periodic law
Explanation:
There are many ways of stating the modern periodic law. Generally, the modern periodic law states that the properties of elements are a periodic function of their atomic numbers. That means, similar properties recur periodically when elements are arranged according to increasing atomic number.
Two scientists were largely responsible for our present day understanding of the modern periodic law, they are, Mendeleev and Moseley. Their work laid the foundation for the periodic table in its current form.
The oxygen atom has 4 valence electrons. Valence electrons are the electrons found in the outermost shell of an atom. These are the electrons that participate in chemical reactions during bonding. Since 4 electrons make up 2 pairs, an oxygen atom is capable of making <em>2 covalent bonds</em>.