Particles constituting substances

important key words that seem unfamiliar :)

What are subatomic particles?

The particles that make up atoms; protons, neutrons, electrons

What is the charge, weight and effect of an electron (in an atom)

• negative charge of -1 or 1-

• mass of about 0.0005u

• determines the chemical properties of an atom

What is the charge, mass and meaning of a proton (-s in an atom)

• positive charge of 1+ or +1

• mass of 1u

• # of protons determines the element’s identity ( Z )

What is the charge, mass and contribution that a neutron has (to an atom)

• no charge (0)

• similar mass to protons of 1u (slightly larger)

• contribute to the mass of the atom and help stabilize the nucleus

What is the atomic number of an atom?

Amount of protons in the nucleus, which is unique to each element

How is mass number A calculated?

A = # of protons + # of neutrons

What’s the average atomic mass (atomic weight) of an element

Element’s weighted average mass of the atoms in a naturally occurring sample of the element

What is an isotope?

Atoms of the same element, but with different mass numbers.

What are the four inner layers of electrons’ letters?

K (n=1), L (n=2), M (n=3), N (n=4)

How is the maximum amount of electrons in an electron shell calculated?

2n²

What’s the difference with the Bohr model and the Lewis diagram?

The Bohr model includes all the shells of the electrons, where the Lewis diagram only includes the valance shell

Name the four electron subshells. How do they work and how many electrons can be in each subshell?

The four subshells are s,p,d,f.

Each electron shell has different subshell combinations:

• K = s

• L = s, p

• M = s, p, d

• N = s, p, d, f

Within each subshell, there is an amount of orbitals:

• s = 1

• p = 3

• d = 5

• f = 7

and each orbital can hold up to 2 electrons.

What significance do valance electrons hold?

They determine most of an atom’s chemical behaviors

• why elements in the main groups have similar behaviors and similar ionic compounds (helium is an exception)

What is the periodic law on atomic radius?

Atomic radius decreases across a period and up a group

explanation:

• Across a period (left to right): Atomic radius decreases because the number of protons increases, pulling the electrons closer to the nucleus due to a stronger electrostatic attraction.

• Up a group (bottom to top): Atomic radius also decreases because the number of electron shells reduces as you move up the group.

What is the periodic law on ionization energy?

Ionization energy increases across a period and up a group

explanation:

• Across a period: Ionization energy increases because atoms have more protons, making it harder to remove an electron due to stronger nuclear attraction.

• Up a group: Ionization energy increases because atoms have fewer electron shells, so the outermost electrons are closer to the nucleus and more tightly held.

What is the periodic law on electronegativity?

Electronegativity increases across a period and up a group

explanation:

• Across a period: Electronegativity increases as the number of protons grows, leading to a stronger pull on shared electrons in a bond.

• Up a group: Electronegativity increases because atoms are smaller, and the nucleus exerts a stronger attraction on bonding electrons.