chem atoms and orbitals test

atom

smallest unit of matter that still has the chemical properties of a larger sample

where do you put the total charge of an atom?

mass number

(protons + neutrons) number of particles in the nucleus

what makes isotopes differ?

they have different numbers of neutrons, ex: hydrogen with 1 neutron and hydrogen with 2 neutrons

rutherford model pros

you can easily count the number of electrons

rutherford model cons

you can’t see the particles in the nucleus well and there’s an unrealistic depiction of electron locations

what test did rutherford do?

he did the gold foil experiment, where he shot particles through gold foil, wondering what the inside of an atom looked like. some were deflected, and some went through, showing him that the atom is mostly empty with a heavy nucleus in the center.

element

different types of atoms, pure substances

atomic theory

1. all elements are made of atoms

2. atoms of the same element are identical

3. atoms of different elements can chemically combine

4. chemical reactions occur when atoms combine, separate, or rearrange with each other to create a different combination of atoms

what makes ions differ?

they are charged atoms with different numbers of electrons

requirements for isotopes

1. must have different numbers of neutrons (different mass number)

2. must have the same number of protons 

weighted atomic mass

average based on how often we find the atom on Earth (natural abundance)

how to find atomic mass

turn percent abundance on Earth into a decimal by dividing by 100, then multiply answer by weight. at the end add all multiplied answers up.

valence shell

outermost shell where electrons are able to bon with other atoms

shell distance from nucleus

shells farther from the nucleus have a higher energy and are less stable

s orbital

spherical orbital shape, 3d area where electrons can be found

p orbital

looks like infinity signs, holds 6 electrons among the 3 p’s (Px, Py, and Pz), each holds 2

how to fill out periodic table for help

issue with orbital diagrams

you can’t see how many electrons are in each orbital

hund’s rule

• each orbital holds a maxiumum of 2 electrons

• electrons prefer to sit alone if possible

aufbau principle

orbitals having a lower energy will fill before higher energy orbitals (lower shells fill before higher shells)

orbital drawing

how to do box notation with p orbitals