Answer:
18.99u or 19u
Explanation:
Mass number=No of protons+No of neutrons


- Fluorine has atomic number=9
- The Electronic configuration is given by

Answer: acceleration can be calculated when a known force is acting on an object of known mass. Newton’s law can be represented by the equation F net = m x a, where F net is the total force acting on the object, m is the object’s mass, and a is the acceleration of the object.
Explanation:
The chemical formular for water is H2O.
The H aspect of the formula stands for hydrogen gas and the subscript 2 which is attached to the H symbol signifies that two atoms of hydrogen are joined together, that is two atom of hydrogen are present.
The chemical formula of water indicates that, two atom of hydrogen react with one atom of oxygen to form one molecule of water.
In chemical formulae, subscripts are normally used to indicate the number of atoms that are present in a molecule.