Covalent bond , hopefully this help :) explanation : .....
Answer:
(1) atomic numbers
Explanation:
The observed regularities in the properties of the elements on the periodic table are periodic functions of their atomic numbers.
- Atomic number is the number of protons in an atom.
- The periodic law states that "the properties of elements are a periodic function of their atomic number".
- Elements on the periodic table are arranged based on the atomic numbers they contain.
- The number of positively charged particles in an atom is the atomic number.
Answer:

Explanation:
Hello there!
In this case, for the reaction by which water is decomposed to molecular hydrogen and oxygen:

It is necessary to perform the inspection balance process since there is a dissimilar number of atoms of oxygen on both sides; therefore, by putting a 2 on water we balance oxygen:

But now, there are four hydrogens on the left; therefore, we put a 2 on hydrogen to finally balance it:

And obviously, the coefficient in oxygen is an unwritten 1.
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Answer:
Dalton's theory are based on the two laws that are: Law of conservation of mass and law of constant composition. This theory basically described their properties of atoms.
This theory state that all the atoms are made up of matter which are invisible and in the elements all the atoms are identical in mass and properties.