Answer:
C.) That all matter was composed of earth, fire, water and air
Explanation:
Just took the test
Answer:

Explanation:
Atomic number : It is defined as the number of electrons or number of protons present in a neutral atom.
However, when we talk about the atomic number of the ion, it is not equal to the number of electrons as electron can be gained or loosed.
This is why, more appropriately, the number of the protons which are present in the nucleus of the atom is called the atomic number.
Thus, atomic number of phosphorus = 15
Mass number is the number of the entities present in the nucleus which is the equal to the sum of the number of protons and electrons.
Given, Mass number = 32
Thus, the symbol of the isotope is:-

Answer:
5kg
Explanation:
Force = Mass x acceleration
F = ma
m = F/a = 10N/2m/s^2
m = 10/2 = 5kg
The standard unit for mass = Kilogram
The standard state of the elements Nitrogen and Oxygen are N2 and O2, knowing that they are diatomic elements. With that piece of information, the unbalanced equation for the formulation of NO2(g) should be as follows -
N2 + O2 ---> NO2
And if you include their states -
N2 ( g ) + O2 ( g ) ---> NO2 ( g )
To balance this chemical equation consider the number of reactants and products on other side of the equation. If you were to include a coefficient of one - half with respect to N2 on the reactant side, it would balance the reactants and products -
A calcium atom has 20 protons!
There you go! I really hope this helped, if there’s anything just let me know! ☻