Atomic Particles

Lesson on Atomic Structure

by Priyanjali

​What is an atom

• ​Atom, smallest unit into which matter can be divided is matter

• ​It has 2 parts : a) Nucleus b) Orbits

• ​It has 3 subatomic particles a) Protons b) Neutrons c) Electrons

• ​

​Subatomic Particles

• ​Protons : Positively charged atomic particles are called protons. These are present in Nucleus. They contribute in the mass of an atom.

• ​Neutrons: Neutrally charged atomic particles are called neutrons. These are present in Neucleus. They also contribute in the mass of an atom.

• ​Electrons: Negatively charged atomic particles are called Electrons. They are present in the orbit of an atom. They have negligible mass so mostly we ignore it.

Fill in the Blanks

Multiple Choice

Which of them is a negatively charged particle

• Electrons

• Protons

• Neutrons

​How to draw an atom

​

Drawing Atomic Structure

1. Draw a circle on the page. For the purposes of this article, we'll use carbon as an example. The process is the same for whatever you're drawing, however. Write a letter "C" in the middle of the circle as an annotation that you're dealing with carbon.

2. Determine how many protons and electrons you'll need to draw. The amount of electrons in an atom is tied to the amount of protons. However many protons you have, that's how many electrons you'll need. To determine the number of protons, you just look at the atomic number. The atomic number for carbon is 6, so you'll need 6 protons, and in turn 6 electrons.

3. Draw your electron rings. The circle with the "C" is a representative nucleus, so now you'll need to indicate the electron orbitals. The number of rings you need is to tied to the number of electrons you have. Carbon has 6 electrons. Since each ring has a maximum number of electrons that can be pictured, you'll have to do some math.

​How to draw an atom-2

​

1. The first ring can have a maximum of 2 electrons, the second ring a maximum of 8, the third ring a maximum of 18, etc. Carbon has 6 electrons, so you'll need to draw two concentric rings.

2. Draw your electrons. You can do this a couple different ways. Some people just draw circles on the rings and fill them in. In this case, you would draw 2 on the first ring and 4 on the second ring. You can also indicate electrons by drawing X's. The best way to draw electrons is to draw them as circles with minus signs inside. This indicates not only that they are electrons, but helps remind the viewer that electrons contain a negative charge.

​How to draw an atom -3

​

1. Draw your protons and neutrons. Erase the "C" in the center circle, and draw in your protons. Since protons are the same as the amount of electrons, you just draw 6 protons. To indicate they are protons, draw them as circles with plus signs contained inside. Neutrons are simply equal to the atomic mass minus the number of protons. Again, you'll need to do some quick math. The atomic mass of carbon is 12, and you have 6 protons. That means you need to draw 6 neutrons in your nucleus. Do not give them an indication of charge, as neutrons are of neutral charge.

2. Label your diagram if you want. It should be clear from your drawing which element is being indicated, but it can never hurt to clarify.

Multiple Choice

What is the atomic number of an atom?

• The number of neutrons

• The number of protons

• The number of electrons

Multiple Choice

Nucleus of an atom whose atomic mass is 24 consists of

• 11 electrons, 11 protons and 13 neutrons

• 11 electrons, 13 protons and 11 neutrons

• 11 protons and 13 neutrons

• 11 protons and 13 electrons

Multiple Choice

what is a atomic number?

• chemical element

• α

• β

Multiple Choice

A charged atom

• Ion

• Isotope

• Electron Cloud

• Quark

Multiple Choice

The negative charge particles that float around the outside of the atom

• Proton

• Neutron

• Electron

Multiple Choice

What scientist first developed 5 rules for atomic theory, and helped kick start modern chemistry?

• J.J. Tomson

• Ernest Rutherford

• John Dalton

• Democritus

Multiple Choice

Who is the first scientist to think that the atom was the smallest unit of matter?

• J.J. Tomson

• Ernest Rutherford

• John Dalton

• Democritus

Multiple Choice

What is the standard unit of mass at the atomic level?

• centimeters

• millimeters

• amu

• milligrams

Multiple Choice

What is the electrical charge of a proton?

• 1+

• 1-

• neutral

• 2-

Multiple Choice

Water is an element

• true

• false

Multiple Choice

DIFFERENT kinds of atoms chemically combined to form a substance are

• Mixture

• Element

• Compound

• Substance

Multiple Choice

Measure mainly of the nuclear particles: protons + neutrons

• Subatomic Particles

• Atomic Number

• Atomic Mass

• Gluons

Multiple Choice

Value representing the number of protons in an element

• Atomic Mass

• Mass Number

• Valence Electrons

• Atomic Number

Multiple Choice

A charged atom

• Ion

• Isotope

• Electron Cloud

• Quark

Multiple Choice

A tiny but very dense, positively charged portion of the atom that holds most of the atomic mass

• Electron Shells

• Orbitals

• Electron Cloud

• Nucleus

Multiple Choice

An atom has 10 protons, 15 neutrons and 10 electrons what is its mass number.

• 20

• 10

• 5

• 25

Multiple Choice

The electron is not included in the calculations for the atomic mass because

• It has negative charge

• It is located in the outer energy levels of the atom

• Hiis mass is basically zero

• It attracts neutral particles

Multiple Choice

The arrow in the picture is pointing to

• The atomic number

• The atomic mass

• The atomic structure

• The atomic charge

Multiple Choice

Find the value of N 45 =  N - 24

• 48

• 21

• 69

• None of the above

Multiple Choice

Complete the missing label on the diagram.

• Neutron

• Centre

• Nucleus

• Sub atomic particle

Multiple Choice

The mass number of an element that has 18 protons, 18 electrons, and 19 neutrons is _____.

• 12.5

• 13

• 25

• 37