Atoms and elements

what in the skibidi toilet rizz are beta decays

Atoms

Atoms

smallest unit of matter that makes up all physical things

What makes up an atom?

Neutrons, Protons, Electrons

Neutrons

neutrally charged particles found in the middle of an atom (not charged)

Electrons

negatively charged particles found floating around the outer parts of an atom

Protons

positively charged particles found in the middle of an atom

What makes up the weight of an atom?

Protons and Neutrons. Electrons are so small that they basically don’t change the mass of an atom

Why are there charged parts in the atom?

Protons and Electrons are charged. Positive & Negative forces are what help atoms be attracted to each other to form different molecules

Elements

a group of the same atom

The type of element of an atom depends on how many protons, neutrons, and electrons it has

Substance

GROUP of different atoms or molecules together

The things that we see are because so many atoms are grouped together that it becomes visible

Diff between atoms, elements, and molecules

atom: 1 lego block

elements: a bunch of blue lego blocks stuck together or a bunch of red lego blocks stuck together

molecules: different colored lego blocks all sticking together

element: substances only made up of 1 type of atom

molecules: substances made up of different atoms bonded together

How many elements are in the periodic table?

Over a 100 right now, but new elements are being synthesized and

Change in protons =

Different elements

Change in neutrons =

ISOTOPES created

Isotopes

Same number of protons, (same element) but has a different weight. A different version of the element

Atomic mass

average of all the isotopes weighted by their % of prevalence

Change in electrons

IONs are created

Ion

positive & negative forces attract other elements to form molecules and bonds. There are several types of bonds

Neutral atoms

Has the same number of protons and electrons (cancels each other out)

• Most atoms are not stable when they are neutral, so they lose or gain electrons to become stable

• This creates a bond between the elements that have gained / lost electrons

If an element gains an electron, it becomes..

a negative ion

if an element loses an electron, it becomes a…

positive ion

How to find the number of neutrons?

1. Round atomic mass to the closest whole number

2. Subtract # of protons from atomic mass

Radioactive decay

unstable nucleus releases energy as protons, neutrons, or rays (changes atomic number and atom)

3 types of radiation

• Alpha particles

• Beta particles

• Gamma Rays

Alpha decay

Alpha particles: 2 protons + 2 neutrons (helium). Changes the element since two protons are removed

CHANGES ATOMIC NUMBER BY -2

Happens to release stability

Beta decay

Electron released when a neutron changes to a proton. This changes the element, since another proton is added.

CHANGES ATOMIC NUMBER BY +1

Happens to release stability

Gamma rays

Sometimes in order for a nucleus to become stable, it just releases excess energy in the form of gamma rays

These rays do not contain any protons or neutrons

CHANGE IN THE ATOMIC NUMBER: 0

Dot diagram

Element symbol, the outermost shell of the element’s electrons are modeled in a clockwise direction

Electron shells

organized in energy levels that can each hold a certain number of electrons. Once a shell is full, the electrons will be added to next level

Diagram energy level order (in to out)

2 8 8

Electron diagram drawing

1. Find element on periodic table, check electron count

2. Draw nucleus and rings around it

3. Add electrons on the rings

4. Shell limits are (2, 8, 8)

Valence electrons

number of electrons on the outermost shell of the diagram

Valence electrons importance

• If the outer shell is not full, the atoms are not stable

• The valence electrons determine what elements an atom can bond to form molecules

• Elements will gain, lose, or share electrons to make their outer shell

Periodic table

Periodic table: chart of elements arranged into rows and columns according to their physical & chemical properties

Used to determine relationships between the elements

PATTERNS OF THE PERIODIC TABLE

• Valence electrons

• Number of protons

• Electron energy levels

• Metals, non-metals, metalloids

• State of matter

• Physical and chemical properties

Very nice elephants make silly plans

• Very = Valence electrons

• Nice = Number of protons

• Elephants = Electron energy levels

• Make = Metals, non-metals, metalloids

• Silly = State of matter

• Plans = Physical and chemical properties

Metals

Luster

Ductile

Malleability

Conductivity

Metals vs other materials

• Higher density

• Greater strength

• Higher boiling point

• Higher melting point

• Most are solid at room temperature

Non-metals

Does NOT conduct electricity

Does NOT luster

NOT ductile/ malleable

Many are gas at room temperature

Metalloids

Contains both metal & non-metal properties

diagonal line on the periodic table starting from boron in 1222

Semi-conductors

elements that conducts electricity at high temperatures but not at low temperatures

Luster

shiny, reflects light

Ductility

can be pulled into wires

Malleability

hammered into thin sheets

Conductivity

electricity and thermal energy pass through easily

if you had to create a new material to make a car engine, how could you use the periodic table to help you?

• Choose elements with high melting points (e.g., tungsten, titanium).

• Ensure strength and durability (e.g., iron, nickel, aluminum).

• Prioritize corrosion resistance (e.g., chromium, platinum).

• Use lightweight materials for fuel efficiency (e.g., aluminum, magnesium).

• Ensure good thermal conductivity (e.g., copper, silver).

• Avoid highly reactive or unsafe elements.