Unit 1 Atoms

Question 1

What is matter

Answer 1

Something that have space and time

Question 2

Symbol of atomic number and atomic mass

Answer 2

Atomic number: z
Atomic mass: A/M

Question 3

Number of neutrons equation, + what is relative atomic mass and mass number

Answer 3

of neutrons = A - z

A= atomic mass (mass of an atom)
z= atomic number

Relative atomic mass: the average of the masses of the isotopes of an element compared to 1/12 of the mass of the carbon-12 atom.

Mass number: The sum of protons and neutrons in the nucleus of an atom (Protons + Neutrons)

Question 4

How to represnt an atom

Answer 4

A up
Ca
Z down

Question 5

The formula for knowing maximum # of cells in each shell

Answer 5

2(n^2)
n= number of shell
Valence shell maximum 8 electrons
That is why noble gases are stable and helium has 2 electrons maximum for shell K

Energy level. Shell letter. e- capacity
1 K 2
2 L 8
3 M 18
4 N 32
5 O 50
6 P 72

Question 6

Ions

Answer 6

Charged atoms

Anions
Negative charged

Cations
Positive charged

Question 7

Isotopes

Answer 7

Each of two or more forms of the same element contains an equal number of protons but a different number of neutrons.

They have different physical properties but pretty similar chemical properties.

Question 8

What does sub atoms determine

Answer 8

Electrons: The # of e- in the valence shell determine the chemical properties.

Protons: Determine the identity of an atom

Neutrons: Determine the isotopes
Atoms with different isotopes of the same atom have different physical properties such as mass number but same chemical properties

Neutrons and protons are also called nucleons because they make the nucleus
That is why atomic mass is also called nucleon number
A= protons + neutrons

Question 9

What is a mole and Avogadro’s constant

Answer 9

A mole is the measurement of atoms/ molecules or other elementary entitles
Avogadro’s constant= 6.02210^23
A mole of carbon contains 6.02210^23 atoms or molecules

Question 10

Mnemonic for first 20 elements of the periodic table

Answer 10

Happy Henry Lives Beside Boron Cottage, Near Our Friend Nelly Nancy
Mg Allen. Silly Patrick Stays Close.
Arthur Kisses Carrie

Question 11

Octet rule and why noble gages are called inert gases

Answer 11

Octet rule: when atoms have 8- in their valence shell they obtain stability

Inert: chemically inactive (خامل)
Noble gases are called inert gases because they are highly
unreactive (stable)

Question 12

Alloys

Answer 12

Homogeneous (same state) Mixture composed of a metal and another metal or sometimes non-metal.
Created to enhance the properties of the original metals, such as strength, hardness, or resistance.