Atomic Number The number of protons in an atom Also, the number of electrons in a neutral atom.

Atomic Number

• The number of protons in an atom

• Also, the number of electrons in a neutral atom

atomic number atomic number atomic number 1 6 79

Atomic Mass

• The number of protons + neutrons in the nucleus

• Since the mass of an electron is soooo much smaller than the mass of protons or neutrons, we do not include it in the atomic mass

Showing atomic number and mass

7 Li 3

3 protons3 electrons7-3 = 4 neutrons

How many protons, neutrons, & electrons?

• An atom that has gained an electron is called an anion. It has a net negative charge.

• An atom that has lost an electron is called a cation. It has a net positive charge.

Isotope

Atoms of the same element that have different atomic masses (but same atomic number)

WHY do they have different atomic masses?

Isotope

• If two atoms are of same element, they MUST have the same number of protons (the same atomic number)

• But…. they can have different number of NEUTRONS. The more neutrons, the heavier the atom

Hydrogen

• Hydrogen is the smallest atom.• Most hydrogen atoms have only one

proton and one electron (no neutrons)

One isotope of Hydrogen has a neutron

Another isotopes of Hydrogen has 2 neutrons

Isotopes of Hydrogen

Isotopes of Lithium

3 neutrons 4 neutrons 5 neutrons

Isotopes of carbon

Atomic Number The number of protons in an atom Also, the number of electrons in a neutral atom.

Documents

Transcript of Atomic Number The number of protons in an atom Also, the number of electrons in a neutral atom.

4.2. ATOMIC NUMBER Elements are different because they contain different numbers of protons. Atomic number = # protons = # electrons in a neutral atom.

Atomic Number Number of Protons. Mass Number Number of Protons + Neutrons.

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Protons and neutrons are called nucleons. An atom is referred to as a nuclide. An atom is identified by the number of protons and neutrons in its nucleus.

REVIEW. WHAT IS ATOMIC NUMBER, Z? THE NUMBER OF PROTONS IN THE NUCLEUS OF AN ATOM – ALSO, THE NUMBER OF ELECTRONS IN A NEUTRAL ATOM.

· Web viewQ1.An atom of aluminium has the symbol (a) Give the number of protons, neutrons and electrons in this atom of aluminium. Number of protons

Number of Protons = Number of Electrons Number of Protons = Atomic Number Atomic Mass = Protons + Neutrons.

Isotopes and Mass Number. Atomic Number The number of protons in each atom identifies it as an atom of a particular element Each atom has a unique number.

Atomic Physics Atomic Notation A X Z X – symbol of the atom Z – atomic number (no of protons) A – mass number 14 C 6 C – carbon Z = 6, the number of protons.

Chemistry Review. The atom Protons, electrons,neutrons.

Atoms and Elements Chapter 1. How do we draw atoms? 1. Look at the Atomic number 2. Atomic number = # protons in the atom 3. # protons = # electrons in.

Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number

1. Neutron A. The number of protons in an atom. 2. Proton B. Hold the electrons around the nucleus. 3. Electron C. The number of protons plus neutrons.

Protons Identify an Element/atom (2 protons = Helium) Protons + Neutrons = Atomic Mass/Weight ( 2 Protons + 2 Neutrons = 4 AMU ) Chemical Properties

The Chemistry of Life · Atomic Number •The number of protons in an atom determines the atom’s atomic number. •For example, an element with the atomic number 2 has 2 protons,

What’s in my atom? Protons = atomic number Electrons = atomic number Neutrons = relative atomic mass –. atomic number Sub-atomic particles Atoms are made.

Every atom has a certain number of protons, neutrons, and electrons.

DETERMINE THE NUMBER OF PROTONS, NEUTRONS AND ELECTRONS IN AN ATOM.

C2 Chemistry An atom: Number of Protons = Number of Electrons Mass number = Protons + Neutrons Periodic table arranges elements by ATOMIC NUMBER (proton.