What is the atomic number and what does it tell you about the number of protons in an atom?

already exists.

Would you like to merge this question into it?

already exists as an alternate of this question.

Would you like to make it the primary and merge this question into it?

exists and is an alternate of .

The number of protons in an atom is the atomic number The number of protons is equal to the atomic number of an atom. It is very important in knowing the number of electrons that surround the nucleus of an atom. In an atom, the electrical charge is neutral, due to the equal number of positive (protons) and negative (electrons) charges. The atomic number represents the protons in an atom and also identifies the element. Hydrogen has one proton. No other atom has just one proton. Heluim has two protons and no other element has only two protons. Lithium has three protons and so on.

The atomic number is equal to the number of protons in the nucleus, and for neutral atoms, it is the same as the number of electrons. In an attempt to keep atoms and ions from getting confused with one another, it is best to think of atoms as always being electrically neutral and ions should be considered charged positively or negatively depending on whether electrons are gained or lost by an atom during the chemical combination of atoms in forming substances such as water, salt and rust found on metals. Protons in atoms and ions are always the same for a specific atom.
Every element has a unique atomic number, and so each element's identity is determined by the number of protons in its nucleus.

However, the same element can have different numbers of neutrons in its nucleus. Two atoms of the same element with two different numbers of neutrons in the nucleus are called isotopes. Also, note that if an atom is not charged (neutral), then the number of protons must equal the number of electrons, and so the atomic number is also equal to the number of electrons in a neutral atom of each element.
However, if the atom is charged (and therefore called an ion), it will have a different number of electrons orbiting it. If the number of electrons is less than the number of protons, it will be a positively charged ion, and the charge will equal the difference between the number of electrons and protons. The same is true if it has more electrons than protons, except now the charge will be negative.


Look under the Web Links below this answer for a periodic table. The number listed for each element is its atomic number. Also see the Related Questions links for more information about the number of protons, neutrons, and electrons in an atom.
93 people found this useful

How do you determine the number of protons in an atom?

The number of protons in an atom determines the chemical identity of that atom. (And only that, by the way.) We use the atomic number to state the exact number of protons in all atoms of a given element. Hydrogen has the atomic number 1 because every atom of hydrogen has exactly one proton. Also, (MORE)

What is the number of protons in the nucleus of an atom?

The number of protons in the nucleus is equal to the atomic number of that atom. Said another way, the atomic number of any element is the number of protons in the nucleus of any atom of that element. It might be helpful to consider some examples, and if we look at mercury, we'll see it has an a (MORE)

Number of proton in an atom?

that would depend on what element your talking about. ie Hydrogen is #1 on the periodic chart, and it has 1 electron and 1 proton. Aluminum is 17? on the periodic chart, and it has 17 electrons and protons. just look at the atomic number, and that's how many it has

Why are the numbers of protons in an atom important?

The necules of an atom consists of protons and neutrons, the protons have apositive charge and the neutrons are neutral. The number of elcetrons always equals the number of protons leaving the atom uncharged.

What is the Number of protons in an atom is called the atomic?

\nDo you mean "Why is the number of protons in an atom called the atoms atomic number?"\n. \nThe defining characteristic of an atom is the number of protons in its nucleus. Hydrogen has one proton. All atoms of hydrogen have one proton. Helium has two protons. If you add a proton to a hydrogen nucl (MORE)

How can you determine the number of protons in an atom?

To find the number of protons in an atom, you look at the atomic mass of the element. The atomic mass is usually located right above the element symbol. It is always a whole number. The atomic number is the number of protons and electrons in an atom.

The average number of protons in an atom?

This question is inadequate; an average number of protons andneutrons has no sense. The number of protons in the known today chemical elements isbetween 1 and 118.

How do your find the number of protons in an atom?

The number of protons in an atom is the "atomic number" on the periodic table. For example, H has 1 proton, He has 2 protons, Li has 3 protons, Be has 4 protons, B has 5 protons, C has 6 protons, N has 7 protons, O has 8 protons, F has 9 protons, Ne has 10 protons, etc.

What are atoms that have the same number of protons?

They are called: Isotopes (of the same element) Example: Three known isotopes of carbon are: . C-12, 6 protons + 6 neutrons in nucleus, mass number 12, most common 99% . C-13, 6 protons + 7 neutrons in nucleus, mass number 13, less common 1% . C-14, 6 protons + 8 neutrons in nucle (MORE)

What is the number of the protons in a atom?

You can find the number of protons by looking at the Periodic Table. The atomic number on the Periodic Table on that specific element tells how many protons and electrons are there. For example, Beryllium has the number 4. That means there are 4 protons and 4 electrons.

What is proton or atomic number?

A proton is a subatomic particle in the nucleus of an atom. Protons have a positive electric charge. The atomic number of an element is equal to the number of protons in the nucleus of one of its atoms. Therefore, if you change the number of protons in an atom, you change the element.

Why do atoms have the same number of protons?

Atoms do not always contain the same number of electrons and protons, although this state is common. When an atom has an equal number of electrons and protons, it has an equal number of negative electric charges (the electrons) and positive electric charges (the protons). The total electric charge o (MORE)