2.1

Question 1

relative charge of proton

Answer 1

1+

actual: +1.60217733 x 10-19

Question 2

relative charge of neutron

Answer 2

0

Question 3

relative charge of electron

Answer 3

• 1

actual: -1.60217733 x 10-19

Question 4

relative mass of proton

Answer 4

1

Question 5

relative mass of electron

Answer 5

1/1836

Question 6

relative mass of neutron

Answer 6

1
actual: measurements shows neutron has slightly greater mass than proton but number is close to 1 so scientists assume protons and neutrons have the same mass

Question 7

where is most of the mass of the atom located?

Answer 7

in the nucleus

Question 8

what is the overall charge of an atom

Answer 8

zero, the atom is neutral as positive charge from protons is cancelled out by negative charge of electrons

Question 9

Why are neutrons considered to be the glue of the atom?

Answer 9

holds nucleus together despite the electrostatic repulsion between protons
an atom will contain same number, if not slightly more, neutrons than protons
as nucleus gets larger, more neutrons are needed

Question 10

how is the periodic table arranged?

Answer 10

in order of increasing atomic number

Question 11

atomic number

Answer 11

The atomic number (proton number) of a chemical element is the number of protons found in the nucleus of every atom of that element. (so every atom of the same element has the same number of protons and different elements contain atoms with different number of protons)

It is identical to the charge number of the nucleus

Question 12

isotope definiton

Answer 12

isotopes are atoms of the same element with different number of neutrons and different masses

Question 13

mass number

Answer 13

the total number of protons and neutrons in an atom

e.g O 16

Question 14

atomic number

Answer 14

number of protons in an atom e.g O 8

Question 15

isotope notation A

Answer 15

A = protons + neutrons

Question 16

isotope notation Z

Answer 16

Z = number of protons

Question 17

how would you find the number of neutrons

Answer 17

mass number - atomic number

Question 18

Why do different isotopes of the same element react in the same way?

Answer 18

chemical reactions involve electrons of an atom
different isotopes of the same element have the same number of electrons
the number of neutrons has no effect on the reaction

Question 19

do isotopes have physical and chemical differences?

Answer 19

NO chemical - react in same way as same no of electrons

YES physical - e.g boiling points, melting points, density

Question 20

ion definition

Answer 20

an ion is a charged particle as a result of losing or gaining an electron

Question 21

what are anions

Answer 21

anions are negative ions, atoms with more electrons than protons and therefore have a negative overall charge

Question 22

what are cations

Answer 22

cations are positive ions, atoms with less electrons than protons and therefore have a positive overall charge