section 5: The Atom Flashcards
What is in the center of the atom?
The nucleus
The nucleus is ____,____, and _____
Small, dense, and positively charged
Protons
Positive charge (p+)
- identifies the elements
- mass= 1 amu
Neutrons
No charge/ neutral (n^0)
- slightly larger in mass than protons (still considered 1 amu though)
- determine isotope
Outside of the nucleus are ______
Electrons
Electrons
1/1837 mass of proton
- determines chemical properties
- # protons = #electrons
Atoms have ___ charge?
Neutral
Atomic number
Number of protons
Atomic mass/Mass number
Number of protons plus neutrons
Today, chemical symbols are based on what?
1 captial letter and/or 1 lowercase letter
Shorthand notation
Used to idenitify atoms/ isotopes
-two types: hyphen notation and nuclear notation
Example of hyphen notation/ nuclear notation
C-12/ 12^6C
Subatomic particles
Particles that are smaller than atoms
- make up atoms
- all particles have opposite “anti” particles
Protons and neutrons are made up of _____
Quarks
Quarks have 6 flavors called _______
Bottom/ top, up/down, strange/ charm
Quarks do not exist alone and are always in groups called _____
Hadrons
Two types of hadrons called _____
Baryons and mesons
Baryons are particles that are made of ____ quarks
3 and ex= protons/ neutrons
Gluons
Force particles that bind quarks into protons and neutrons
Leptons
Six types: Electons, tau, muons, and 3 neutrinos
Opposite of electron is ____
Positiron (same mass and e- but + charge)
Reminder on how to find subatomic particles
+
Strong nuclear
Holds protons and neutrons together in the nucleus
Electromagnetism
Opposite charges attract/ likes repel
Weak nuclear
Holds the neutron together (how we get beta decay)
Gravity
Attraction b/w objects with mass
Radioactivity
Process of an unstable nucleus emitting one or more particles of energy in the form of electromagnetic radiation
Nuclear decay (process)
Process of atom’s nucleus changing by releasing energy/ particles to form a different element
Nuclear radiation (result)
Charged particles of energy emitted by an unstable nucleus
How many types of nuclear radiation are there/what are they?
4- alpha, beta, gamma, and neutron
Alpha particles are _____
Large and +2 charge (basically a He nucleus)
-dont travel far and are stopped by skin and clothes
Beta particles are ______
Very small and fast moving
- -1 or +1 charge
- formed from a decaying neutron
- smaller and can penetrate more substances (stopped by 3mm of Al)
Gamma rays are _____
High energy electromagnetic radiation
- far penetrating bc they have no mass
- more damaging to health
Neutron emission are _____
No charge and increased energy
- result of n^0 nuclei (large elements)
- damaging
Alpha decay
Element loses 2p and 2n
Beta decay
Mass # doesnt change but the atom gains protons
Gamma decay
No change in atomic #, just a change in energy
Half life
The time required for half a sample of radioactive nuclei to decay
