# Inside the Atom.

## Presentation on theme: "Inside the Atom."— Presentation transcript:

Inside the Atom

Let’s Investigate the Atom

Atoms are composed of three type of particles: SUBATOMIC PARTICLES: protons, neutrons, and electron.
Protons and neutrons are responsible for most of the atomic mass of an atom, while electrons contribute a very small amount of mass(9.108 X grams).

What makes up the atom. Protons and neutrons reside in the nucleus
What makes up the atom? Protons and neutrons reside in the nucleus. Protons have a positive (+) charge, neutrons have no charge. They are neutral. Electrons are in orbitals, or electron clouds, around the nucleus. They have a negative charge (-).

Atomic Number The number of _________ in the nucleus of an atom determines an element's atomic number. The number of protons in the nucleus of an atom determines an element's atomic number.

So what is the Atomic Number?

C 6 Atomic number. Atomic symbol Carbon 12.011 Element name
Average atomic mass - *To find the number of protons, see the atomic number. *To find the number of electrons (see the atomic number, adjust for charge if there is one) *To find the number of neutrons, subtract the atomic number from the atomic mass. Use whole number. Atomic mass Atomic # 6 neutrons

The number of electrons, protons, and neutrons can be changed in an atom and changes the atom!

I. Changing Electrons An atom that changes the number of electrons is called an __________. The number of ________ and ________ stays the same. No change in atomic number or ____________ ______________. An atom that changes the number of electrons is called an ion. The number of protons and neutrons stays the same. No change in atomic number or mass number.

II. What is make an ion? If the atom loses electrons, the atom becomes ____________ charged. If an atom gains electrons, the atom becomes ____________ charged. If the atom loses electrons, the atom becomes positively charged. If an atom gains electrons, the atom becomes negatively charged.

Positive ion______________
(4 +) + (3-) = 1+

Negative ion______________
(4 +) + (5-) = 1-

III. Changing Neutrons Changing the number of neutrons in an atom makes an ________________. Have the same _______ _____________ Have different mass numbers (number of __________ + ___________) Changing the number of neutrons in an atom makes an isotope. Have the same atomic number(number of protons)) Have different atomic mass numbers (number of protons + neutrons

IV. Changing Protons Changing the number of protons causes ________________- changing from one element to another. The _________________and __________________ changes Changing the number of protons causes transmutation changing from one element to another. The atomic number and mass number changes

Sample Problem 1: For an atom with 15 protons, 16 neutrons, and 18 electrons…
What is the atom’s net charge? What is the atomic number of the atom? What is the mass number? This is an atom of what element?

Sample Problem 2: For an atom with 28 protons, 31 neutrons, and 26 electrons…
What is the atom’s net charge? What is the atomic number of the atom? What is the mass number? This is an atom of what element?

Vocabulary 79. Democritus 80. John Dalton 81. Atomic theory
82. J.J. Thomason 83. Ernest Rutherford 84. Niels Bohr 85.James Chadwick Electron clouds Nucleus Protons Neutrons Electrons Atomic mass Atomic number Ion Isotope Transmutation