Chemistry Unit Test Flashcards
What are the 3 types of Sub-atomic particles and how do you find their number on the periodic table?
Proton- Atomic Number
Neutron- Subtract # of protons from mass number
Electron- Same as protons
How many groups of elements does the periodic table have?
18
What are valence electrons and how can you use the periodic table to determine the number of them in an atom?
They are the electrons found in the outermost energy level of an atom, on the periodic table, use the group number but drop the teen
What are the number of valence electrons for Hydrogen, Calcium, Oxygen,and Neon
Hydrogen-1
Calcium-2
Oxygen-6
Neon-8
What are the noble gases and describe their bonding abilities
They are Neon, Argon, Krypton, Xenon, Radon, they do not form bonds with other atoms because they already have a full valence shell
Why atoms considered neutral?
The number of electrons equal the number of protons
Define and give an example of an ionic bond
bond that forms when electrons are transferred from one atom to another, which results in a positive and negative ion.-NaCl
Define and give an example of a metallic bond
bond formed by the attraction between positively charged metal ions and the electrons around them- block of silver
Define and give an example of a covalent bond
bond formed when atoms share one or more pairs of electrons- H2O
Define Crystal Lattice
the regular patterns in which a crystal is arranged
Define ion(s)
CHARGED particles when atoms gain or lose electrons
Define atom(s)
NEUTRAL (no charge) because # of protons equal the # of neutrons
Define diatomic molecule and give 3+ examples
atom make of 2 of the same molecules- Hydrogen, Oxygen, nitrogen, Fluorine, Chlorine, Bromine, Iodine
Define chemical reaction
when one or more substances change to produce one or more different products
what are the four signs of a chemical reaction?
Gas formation, solid formation, energy change, color change
what happens during a chemical reaction?
bonds break, new bonds form, new substance created
define product
substance that forms in a chemical reaction
define reactant
substance that participates in a chemical reaction
what does the law of conservation of mass state?
Mass cannot be created nor destroyed in a chemical reaction
synthesis reaction
2 substances combine to form 1
decomposition reaction
compound breaks down to form 2 or more substances
single displacement reaction
1 element replaces another
double displacement reaction
ions from 2 compounds exchange places
define exothermic
energy (heat) RELEASED in a chemical reaction
define endothermic
energy (requires heat) is taken in during a chemical reaction
define activation energy
minimum amount of energy need to start a chemical reaction- striking a match, spark in a car’s engine, light
define acid and give properties
liquid with pH level below 7- sour flavor, many corrosive, react with metals, conduct electric current
define base and give properties
liquid with a pH level above 7- bitter flavor, many corrosive, slippery feel, conduct electric current
define indicator and give examples
substance that changes color in the presence of an acid or base- bromythol blue, pH paper, pH meter, litmus paper strips
what 2 substances are always produced in chemical reaction
a salt and water
in chemistry, what is a salt?
an ionic compound that forms when a metal replaces the hydrogen of an acid
define radioactivity
process by which an unstable nucleus gives off nuclear radiation
name the 3 types of radioactive decay
alpha, beta, gamma
which RD has the most penetrating power?
gamma
name one use of radioactivity in home, industry, and healthcare
home- smoke detectors
industry-space probes
healthcare- tracers
Define isotope
atom that has the same number of protons as other atoms of the same element but have a different number of neutrons
define half-life
time needed of half a sample of a radioactive substance to undergo radioactive decay
fission
splitting of the nucleus of one large atom into 2 or more fragments
fusion
combo of nuclei of small atoms to form a larger nucleus
what process occurs in nuclear power plants?
fission
what process occurs in the sun’s core, what state of matter is found, and what temp does it have to be?
Fusion- state of matter- plasma- more than 100,000,000 degrees celsius
fusion advantages
less accident prone, less waste, endless supply of fuel in the oceans
fusion disadvantages
difficult to create, more energy used to create than is produced
fission advantages
cost less that plants that use fossil fuels, no pollution
fission disadvantages
more accidents, must be stored until it becomes less radioactive
