Chapter 4

Question 1

Atom

Answer 1

smallest building block of matter

Question 2

Atomic mass unit

Answer 2

1/12th of the mass of a carbon-12 atom

Question 3

isotope

Answer 3

an atom with the same number of protons but a different number of beauteous in its nucleus

Question 4

Relative atomic mass

Answer 4

The mass of the element compared with the mass of a carbon-12 atom

Question 5

Electron configuration

Answer 5

the arrangement of electrons in an atom

Question 6

Pauli’s Exclusion Principle

Answer 6

Electrons of opposite spin occupy the same orbital

Question 7

Hund’s Rule

Answer 7

Electrons enter orbitals singly before pairing up

Question 8

Valence electrons

Answer 8

the electrons in the outermost energy level of the atom that will determine how an atom will react in a chemical reaction

Question 9

core electrons

Answer 9

the remaining electrons that make up the atom

Question 10

In 4 bullets, describe Dalton’s theory regarding to the building blocks of matter

Answer 10

• All matter is made up of small indestructible particles called atoms
• Elements are made up of atoms of the same sort
• Different elements have different types of atoms
• Atoms combine in fixed ratios to form compounds

Question 11

what 2 sub atomic particles contribute to the mass of an atom

Answer 11

• protons

* neutrons

Question 12

Give the mass of atoms in kg’s

Answer 12

1,66 x 10(exponent) -27 kg

Question 13

what sub atomic particle contributes to the volume of an atom

Answer 13

electron

Question 14

what is an electrons charge?

Answer 14

1,6 x 10 (exponent) -19 C

Question 15

please look at that table thingy

Answer 15

dankie liefie

Question 16

Give 4 characteristics of the nucleus

Answer 16

• nucleus is positively charged
• particles held together by very strong nuclear forces = overcome repulsive forces protons have on each other
• enormous amount of energy required to split the nucleus
• chemical reactions only influence electrons & not nucleus

Question 17

How could you calculate the number of neutrons in the nucleus?

Answer 17

atomic mass number - protons

Question 18

practice Ar

Answer 18

👅

Question 19

Electron configuration & Aufbau

Answer 19

PLEASE

Question 20

what’s the difference between core electrons and valence electrons?

Answer 20

Valence electrons:
determine how the atom will behave in chemical reactions -> electrons in outer most energy level

Core electrons:
remain attached to the atom during chemical reactions & requires an enormous amount of energy to remove -> all the other electrons