chap 3

Question 1

what is an atom?

Answer 1

an atom is the smallest particle that can still have the characteristics of an element

Question 2

what is the relative mass and charge of a proton?

Answer 2

relative mass: 1
relative charge: +1

Question 3

what is the relative mass and charge of a neutron?

Answer 3

relative mass: 1
relative charge: 0

Question 4

what is the relative mass and charge of an electron?

Answer 4

relative mass: 1/1840
charge: -1

Question 5

what is the nucleon (mass) number?

Answer 5

number of protons + number of neutrons. it is also known as the relative atomic mass.

Question 6

what is the nuclide notation?

Answer 6

number on top: relative atomic mass
number at the bottom: proton number
^12 C can be expressed as carbon-12

Question 7

what are isotopes?

Answer 7

isotopes are atoms of the same element with the same number of protons and electrons but a different number of neutrons. since the proton number of the isotope remains unchanged, the isotopes belong to the same element

Question 8

why do isotopes have similar chemical properties?

Answer 8

chemical reactions only involve the outermost electrons and not the protons and neutrons. for example, chlorine-35 and chlorine-37 will react with sodium to form sodium chloride

Question 9

why do isotopes have different physical properties?

Answer 9

physical properties are affected by mass. for example, hydrogen-2 has a slightly higher melting point, boiling point and density than hydrogen-1