Vocab
atomic number is equal to the number of:
protons
On earth, matter usually occurs as:
solid, liquid, gas
in a chemical bond, each element has _____ electrons in the outermost layer
2
an atom that gains or loses electrons and is a charged particle:
ion
True/false: matter cannot be created or destroyed
Most abundant elements in the universe are:
hydrogen and helium
mass number is equal to ______ plus ______
protons plus neutrons
a substance that produces hydroxide ions:
base
forces that hold elements together in a compound
chemical bond
there are only three states of matter in the universe
FALSE
_______ and _______ are 75% of the crust of Earth
oxygen and silicon
elements with a full outermost energy level are highly reactive or unreactive
unreactive
a substance that produces hydrogen ions:
acid
chemical reaction
Hot, highly ionized, electrically conducting gas is known as:
plasmas
elements that contain oxygen and silicon are known as:
silicates
each element has unique _________ and ________ properties
chemical and physical
most solids are known as _________ __________ because they are arranged in regular geometric patterns:
crystalline structure
True/false: most solids have a crystalline structure where particles are arranged in geometric patterns
TRUE
particles are close together but able to move relative to one another in their container:
lquid
the attraction of two atoms for a shared pair of electrons is what type of bond:
covalent bond
oxygen and hydrogen are highly __________ on their own, but combined they form _______
flammable ; water
a substance that is composed of atoms of two or more different elements are chemically combined:
compound
True/False: the change of state from solid to gas without an in between liquid state is called evaporation
FALSE
helium is an example of which state of matter is:
gas