I. Match the following. 1.a minus-charged particle of an atom
2.a neutral (no charge) particle found in the nucleus of an atom
3.a positive-charged particle in the nucleus of an atom
4.a system of comparing atomic masses to carbon

a. proton
b. relative mass
c. electron
d. neutron

II. The atomic number of an atom is equal to the number of

a. neutrons
b. electrons
c. protons

III. The atomic number is always equal to the atomic mass.

True
False

IV. Atomic mass minus atomic number =

atomic mass
number of electrons
number of neutrons
number of protons

V. A proton in the nucleus of an atom has an electrical charge of:

neutral
-
+
zero

VI. The atomic number of calcium is 20. This number means that calcium has 20 protons. The atomic mass of calcium is 40. How many neutrons does calcium have? (Remember: protons + neutrons = atomic mass.)

a. 40
b. 60
c. 20

VII. Helium has an atomic number of 2. This number also means that helium has 2 protons. The atomic mass of helium is 4. How many neutrons does helium have? (Remember: protons + neutrons = atomic mass.)

a. 2
b. 4
c. 6

VIII. The relative atomic mass of a proton or neutron is

a. 1
b. 2

IX. The relative atomic mass is always a mass that is compared to the element

a. carbon
b. oxygen
c. hydrogen

X. Name the three kinds of sub-atomic particles found in an atom:

a. Protons
b. Electrons
c. Neutrons
d. Polyhedrons
e. Axons

I.

1. a minus-charged particle of an atom Electrons

2. a neutral (no charge) particle found in the nucleus of an atom Neutrons

3. a positive-charged particle in the nucleus of an atom Protons

4. a system of comparing atomic masses to carbon Relative mass

II. The atomic number of an atom is equal to the number of Protons.

III. The atomic number is always equal to the atomic mass. False.

IV. Atomic mass minus atomic number =number if neutrons.

V. A proton in the nucleus of an atom has an electrical charge of: +ve (positive).

VI. The atomic number of calcium is 20. This number means that calcium has 20 protons. The atomic mass of calcium is 40. How many neutrons does calcium have?

No of neutrons = atomic mass-atomic number

No of neutrons= 40-20=20 neutrons.

VII. Helium has an atomic number of 2. This number also means that helium has 2 protons. The atomic mass of helium is 4. How many neutrons does helium have?

No of neutrons = atomic mass-atomic number

No of neutrons= 4-2=2 neutrons.

VIII. The relative atomic mass of a proton or neutron is 1.

IX. The relative atomic mass is always a mass that is compared to the element Corbon.

X. Name the three kinds of sub-atomic particles found in an atom: electron, proton and neutron

he forelimbs below belong to four species that descended in a direct line from the ancestral mammal shown above. of the four descendants shown, which species most likely appeared earliest in evolutionary history?