atom / the basic building block of matter - the smallest particle of an element that still has all the properties of that element
atomic mass / a number equal to the sum of the number of protons and neutron in an atom’s nucleus
atomic number / the number of protons in the nucleus of an atom
amu = atomic mass unit / A unit of mass equal to 1/12 the mass of an atom of the most common isotope of carbon (carbon 12), which is assigned a mass of 12. A hydrogen atom has a mass of 1 atomic mass unit since its mass is 1/12 the mass of carbon 12.
brittle / easily broken, cracked, or snapped
example: brittle clay or brittle glass
buoyancy / the upward force that a fluid exerts on an object that is less dense than itself.
Example: buoyancy allows a boat to float on water
buoyant force / upward force exerted on an object immersed in a fluid
charge / an electrical property that can be either positive or negative
chemical equation / shorthand form for writing what reactants are used and what products are formed in a chemical reaction; sometimes shows whether energy is produced or absorbed.
chemical equation / a description of a chemical reaction written with chemical formulas, subscripts and coefficients
chemical property / characteristic that can NOT be observed without altering the sample - it also determines how a substance will react with another substance
chemical change / a change in which substances become new substances with different properties
chemical formula / a group of chemical symbols and numbers that shows the kinds and numbers of atoms in a molecule
CH 4
chemical reaction / a process in which elements and compounds combine in new ways to form new substances
chemical symbol / a code, normally composed of one or two letters used to represent an element
CH 4
coefficient / a number written before a chemical formula to show how many atoms or molecules of that substance are involved in a reaction
compound / a substance produced when elements combine and whose properties are different from each of the elements in it
compound / a substance that forms when two or more elements join chemically
conduction / transfer of (heat) energy that occurs when molecules bump into each other
conductor / A material or an object that conducts heat, electricity, light, or sound.
Copper is a good conductor of electricity.
density / mass of an object divided by its volume
ductile / Easily drawn out into a few strand or wire. Gold and silver are ductile metals.
electron / negatively charged particle that exists in an electron cloud formation around an atom's nucleus
electron cloud / region surrounding the nucleus of an atom, where electrons are most likely to be found
electrical charge / a property of matter; charge can be positive or negative
element / substance that cannot be broken down into simpler substances by ordinary means - has unique properties and is generally classified as a metal, metalloid or nonmetal
endothermic reaction / chemical reaction in which heat energy is absorbed
exothermic reaction / chemical reaction in which heat energy is released
family / a group or organisms ranking above a genus and below an order
flammability / easily set on fire
ignitability, sustainability, combustibility, and consumability
group / a column in the periodic table
-family of elements in the periodic table that have similar physical or chemical properties
heat / transfer of (heat) energy from one object to another due to a difference in temperature - flows from water objects to cooler objects
inorganic / a compound that does not contain carbon
inert / unable to react chemically
insulator / To cover or surround with a material that prevents the loss or transfer of heat, electricity, or sound
ion / a charged atom
isotope / two or more atoms of the same element that have different numbers of neutrons in the nuclei (same number of protons)
Law of conservation of mass / states that mass is neither created nor destroyed and as a result the mass of the substances before a physical or chemical change is equal to the mass of the substances present after the change ---- the mass of the products = the mass of the reactants
law of conservation ofmatter / states that matter is not created or destroyed it simply changes form
luster / the way a mineral reflects light
magnetic / having the properties of a magnet; showing magnetism
malleable / capable of being shaped or formed in its solid state, especially bypressure or hammering
gold is the most malleable substance known
mass number = atomic mass / the sum of neutrons and protons in the nucleus of an atom
mass / the amount of matter in an object
matter / anything that takes up space and has mass
metal / element that has luster, is malleable and ductile and is a good conductor of heat and electricity
metalloid / element that shares some properties with metals and nonmetals, it is a solid a room temperature
mixture / a composition of two or more substances that are not chemically combined with each other and are capable of being separated
molecule / a group of two or more atoms held together by very strongchemical bonds, - the smallest unit of a compound that has all the properties of that compound
neutron / electrically neutral = no charge = particle that has the same mass as a proton and is found in an atom's nucleus
nonmetal / element that is usually a gas or brittle solid at room temperature and is a poor conductor of heat and electricity, nonmetals are the basic chemicals of life
nucleus (atom) / positively charged central part of an atom (contains both protons and neutrons)
organic /
- involving organisms or the products of their life processes
- relating to chemical compounds containing carbon, especially hydrocarbon
period / horizontal row of elements in the periodic table whose properties change gradually and predictably
physical property / characteristic that can be observed, using the five senses, without changing or trying to change the composition of a substance
physical change / change in which the form or appearance of matter changes, but not its composition/identity
product / substance that forms as a result of a chemical reaction
proton / positively charged particle in the nucleus of an atom and when the number of protons are counted it is used to identify the element (atomic number)
precipitate / a solid that forms during a chemical reaction that takes place in a solution
properties / Are the characteristics of a substance
The way a substance tastes, smells, color, etc.
pure substance / a substance that has the same chemical composition through and cannot be separated into its parts by physical means
H2O
reactant / substance that exists before a chemical reaction begins
reactivity / a chemical property that describes how likely an element is to form bonds with other elements
The rate at which a chemical substance tends to undergo a chemical reaction.
solubility / Capable of being dissolved
subatomic particle / one of the basic units of which atoms and all matter are made -protons, neutrons and electrons are subatomic particles
subscript / a number written to the right and slightly below a chemical symbol to identify how many atoms of an element are in a molecule
H2O
sublimation / the process of changing from a solid to a gas , or from a gas to a solid, without passing through an intermediate liquid phase
temperature / measure of the kinetic energy of the atoms of an object
valence electron / an electron in an atom's outermost energy level
volume / the amount of space occupied by three-dimensional object or region of space
solid / one of the three basic forms of matter composed of molecules that have little or no ability to exchange places -fixed volume
liquid / one of the three basic forms of matter, composed of molecules that can move short distances
-no fixed shape, usually has volume
gas / one of the three basic forms of matter, composed of molecules in constant random motion
-no fixed shape, takes shape of space available