Unit 1-- Matter, chemical trends, & chemical bonding Flashcards
What is all matter composed of?
Atoms
What are the 3 sub-atomic particles?
Protons, Neutrons, and Electrons
How are ions formed?
When an atom gains or loses an electron, it becomes an ion and is no longer neutrally charged
ions
Charged atoms
Define ISOELECTRONIC
Atoms/Ions that have the same number of electrons
same number of valence electrons.
ANION
An atom that gains electrons becomes NEGATIVELY charged
CATION
An atom that loses electrons and becomes POSITIVELY charged
Two or more forms of the same element that have the same number of protons but a different number of neutrons
ISOTOPES
Can differ in mass and there can be heavy and light forms of an element
ISOTOPES
ELECTRON PAIRS
Two electrons interact in a unique way, allowing them to be situated close to each other
UNPAIRED ELECTRONS
Electrons that are in an unfilled outer shell and do not have pairs.
They are more likely to participate in atom bonds
ATOMIC MASS UNIT
U
a measure of its atomic mass.
it is one-twelfth of the carbon-12 atom
BETA PARTICLE
High energy particles that are negatively charged, and are ejected from the nucleus when the nucleus is unstable and unbalanced
AVERAGE ATOMIC MASS
The average of the masses of all the elements isotopes
How are BETA particles formed?
emitted from an atom’s nucleus during radioactive decay.
RELATIVE ATOMIC MASSES
The weight in grams of the number of atoms of the element contained in 12.00 g of carbon-12
STRONG NUCLEAR FORCE
the force that holds protons and neutrons together.
RADIOSOTOPES
Isotopes with unstable nuclei that decay into different, often more stable isotopes
ISOTOPIC ABUNDANCE
The percentage of atoms with a specific atomic mass found in an element
How many isotopes is CARBON made of
2!
Carbon-12 & Carbon-13
What holds the nucleus ( protons and neutrons) together
STRONG NUCLEAR FORCE
ENERGY LEVELS
fixed distances from the nucleus of an atom where electrons may be found
BOHR MODEL
consists of a small, dense nucleus surrounded by orbiting electrons.
LEWIS DOT DIAGRAMS
use dots to represent valence electrons around an atomic symbol.
OUTERMOST ELECTRONS
VALENCE ELECTRONS
1st energy level
Holds 2 electrons
2nd energy level
Holds 8 electrons
3rd energy level
Holds 8 electrons
OCTET RULE
This tendency to gain or lose electrons
is called the
PERIODIC LAW
A statement that describes the repeating nature of the properties of the elements
PERIOD
Rows on the periodic table of elements
GROUP
Columns on the periodic table of elements
METALLOIDS
Along both sides of the staircases and demonstrate both metal and non-metal properties
HALOGENS
-Many are are liquids or gases
- Very poisonous
- Reactivity increases UP the group
NOBLE GASES( INERT GASES)
– All are gases
- Do not react with anything
ALKALINE EARTH METALS
- Solids
-React with metals less dramatically than less active metals
-Reactivity increases DOWN the group
ALKALI METALS ( ACTIVE METALS)
- Solids
- Very reactive and reacts violently with water
- Reactivity increases DOWN the group
When elements are arranged by atomic number, their chemical and physical properties recur periodically
PERIOD LAW
ATOMIC RADIUS
the total distance from the nucleus of an atom to the outermost orbital of its electron.