The document describes the three main subatomic particles that make up atoms: protons, neutrons, and electrons. Protons are positively charged and located in the atom's nucleus. Neutrons have no charge and are also in the nucleus. Electrons are negatively charged and orbit the nucleus. The atomic number of an element is the number of its protons, which also determines the number of electrons. The mass number is the total number of protons and neutrons. Isotopes are atoms of the same element that have different numbers of neutrons.

1. SUBATOMIC
PARTICLES
 PROTON
 NEUTRON
 ELECTRON
SHIELA MARIE B. SIBAYAN
Teacher I

2. Learning Objectives:
 Describe the subatomic particles
 Identify the number of protons,
electrons, neutrons, mass number and
atomic number in given isotope
 Define isotopes

3. What are atoms
made of?
-tiny, very light particles
-have a negative electrical charge (-)
-move around the outside of the
nucleus
ELECTRONS

4. +
+
+
-
-
-
ELECTRONS

5. What are atoms
made of?
-much larger and heavier than electrons
-protons have a positive charge (+)
-located in the nucleus of the atom
PROTONS

6. +
+
+
-
-
-
PROTONS
ELECTRONS

7. What are atoms
made of?
-large and heavy like protons
-neutrons have no electrical charge
-located in the nucleus of the atom
NEUTRONS

8. +
+
+
-
-
-
PROTONS
NEUTRONS
ELECTRONS

9. Atomic Number
and Mass Number
Atomic Number
All atoms can be identified by the number of
protons and neutrons they contain.
The atomic number (Z) determine the identity
of an element.
It is the number of protons in the nucleus
Atoms are neutral, so it’s also the number of
electrons.

10. Therefore,

11. Elemental
symbol
X
Z
A
Atomic number
(number of protons
and number of
electrons)

13. Atomic Number
and Mass Number
Mass Number
The mass number (A) is the total number
of protons and neutrons.
Protons and neutrons are collectively
referred to as nucleons.

14. Elemental
symbol
X
Z
A
Mass number
(number of protons
+ neutrons)
Atomic number
(number of protons
and number of

15. 3
7 Element
(Lithium)
Mass number
(7)
Atomic number
(3)

16. Therefore,

17. Rewriting the formula,
we have:

18. Note that the atomic
number is the same
as the number of
protons and
electrons….

20. 8
16
Oxygen

21. 8
16

22. 8
16

23. 8
16

24. 8
16

25. 35

26. Zinc
30
30
30
35
65

27. Most elements have two or
more isotopes, atoms that have
the same atomic number (Z)
but different mass numbers
(A).

28. 1 proton
0 neutrons
1 proton
1 neutron
1 proton
2 neutrons

29. Define the following:
a.protons
b.electrons
c.neutrons
d.isotopes

30. Element:____________
Atomic Number:______
Mass Number:________
No. of Protons:________
No. of Electrons:_______
No. of Neutrons:_______
Element:____________
Atomic Number:______
Mass Number:________
No. of Protons:________
No. of Electrons:_______
No. of Neutrons: 6
Complete the information below for each
given isotope:

31. Element:____________
Atomic Number:______
Mass Number:________
No. of Protons:________
No. of Electrons:_______
No. of Neutrons: 42
Element:____________
Atomic Number:______
Mass Number:________
No. of Protons:________
No. of Electrons:_______
No. of Neutrons:______
Complete the information below for each
given isotope: