Chemistry Review

Question 1

How do you find the number of neutrons?

Answer 1

Mass number subtracted by the protons

Question 2

What is the nucleus made up of?

Answer 2

Neutrons and protons

Question 3

What must an atom have to remain neutral?

Answer 3

Equal number of protons and electrons

Question 4

How do you find the mass number?

Answer 4

Add the protons and the neutrons

Question 5

What is an Isotope?

Answer 5

Atoms of the same element but different number of neutrons

Question 6

What is Atomic mass?

Answer 6

This is the weighted average of various isotopes

Question 7

Bohr Rutherford diagrams

Answer 7

A nucleus surrounded by orbitals is useful because it helps show the visualization electrons orbiting a nucleus

Looks like a planet surrounding my orbitals

Question 8

Lewis dot diagram

Answer 8

show the bonding between atoms of a molecule by only showing the valence electrons

Question 9

What happens when atoms lose electrons?

Answer 9

they become positively charged and turns into a cations

Question 10

What happens when atoms gain electrons?

Answer 10

they become negatively charged and turns into a anions

Question 11

what is a covalent bond?

Answer 11

a bond that usually exists between elements that are nonmetal when two atoms share electrons for example water

Question 12

what are ionic bonds?

Answer 12

chemical formed between oppositely charged elements

for example sodium and chlorine

Question 13

what is a molecular formula?

Answer 13

a formula stating the number of atoms in each element

Question 14

what is a structural formula?

Answer 14

a drawing of atoms connected by chemical bonds

lines connecting the symbols of elements

Question 15

what are structural isomers?

Answer 15

molecules that have the same molecular formula, but have a different arrangement of the atoms in space

Question 16

what is the hill system?

Answer 16

using the acronym CHNOPS to write the molecular formula

Question 17

what are orbitals?

Answer 17

a mathematical region around a nucleus that may contain electrons

Question 18

what are energy levels?

Answer 18

Energy levels (also called electron shells) are fixed distances from the nucleus of an atom where electrons may be found

Question 19

what are valence electrons?

Answer 19

an electron in the outermost shell of an atom that can form chemical bond with another atom

Question 20

what is electronegativity and what is its trend on the periodic table/

Answer 20

it is the ability of an atom to attract electrons

it increases moving right and up

decreases moving left and down

fluorine is the most electronegative element

Question 21

what is a non polar covalent bond?

Answer 21

when electrons are shared equally between two atoms

this is usually seen with diatomic molecules

Question 22

polar covalent bond?

Answer 22

when two atoms share electrons unequally

Question 23

what is the meaning of hydrophilic?

Answer 23

elements that dissolve in water ionic compounds such as salt

Question 24

what is the meaning of hydrophobic?

Answer 24

elements that don’t dissolve or repel water such as oil

Question 25

how are ionic compound formed?

Answer 25

when there is a complete transfer of an electron in a bond

Question 26

what is polarity dependent on?

Answer 26

the electronegativity of an atom and the molecular shape whether it it is asymetricalorsymetrical

Question 27

what does it mean if a molecule is asymetrical?

Answer 27

the molecule is nonpolar if all the bonds are nonpolar
or the molecule is polar if at least one bond is polar

Question 28

what determines the chemical behaviour of an atom

Answer 28

the number and arrangement of the atom’s valence electrons

Question 29

what are the steps of making a Bohr Rutherford diagram?

Answer 29

1. draw the nucleus with the proton and neutron numbers inside
2. place the electrons on their energy levels