When greater amounts of energy are required eto break existing bonds. The energy is therefore absorbed.
What is ENDOTHERMIC REACTION
100
Electron dot diagrams to show their placement in atoms
What is LEWIS STRUCTRE
100
While studying the effect of x-rays on photographic film, he discovered some chemicals spontaneously decompose and give off very pentrating rays.
What is Henri Becquerel
100
measures the average amount of kinetic energy in a sample mass.
What is TEMPERATURE
200
When one atom donates a pair of electrons to be shared with an atom or ions that need two electrons
What is COORDINATE COVALENT BONDS
200
The starting substance
What is REACTANTS
200
model used to determine molecular shape
What is VSEPR
200
Studied radiations emitted from uranium and thorium and named them alpha and beta.
What is RUTHERFORD
200
determines how compact the molecules are in a sample of mass.
What is DENSITY
300
When parallel orbitals overlap to share electrons
What is PI BONDS
300
Substances formed during a chemical reaction.
What is PRODUCTS
300
Three equivalent structures used to represent the same ion.
What is RESONANCE
300
Developed an explanation of atomic structure that underlies regularities of the periodic table of elements. His atomic model had atoms built up of sucessive orbital shells of electrons.
What is BOHR
300
Determines the force per unit area
What is PRESSURE
400
Bond formed when there is an unequal sharing of electrons
What is POLAR COVALENT.
400
A solid formed during a chemical reaction in a solution.
What is PRECIPITATE
400
molecular models that use the letter symbols and bonds to show the relative position of the atoms.
What is STRUCTURAL FORLMULA
400
Using alpha particles discovered a neutral atomic particle with a mass close to a proton. Thus was discovered the neutron.
What is CHADWICK
400
determines the quantity of space that an object takes up
What is VOLUME
500
Formed between the sharing of electrons bewteen nonmetals.
What is COVALENT BONDS.
500
When the energy is realeased during a reaction in order to form new bonds.
What is EXOTHERMIC REACTION
500
Process in which the atomic orbitals are mixed to form new identical orbitals.
What is HYBIRDIZATION
500
Arranged elements into 7 groups with similar properties. He discovered that the properties of elements "were periodic functions of the their atomic weights". This became known as the Periodic Law
What is MEENDELEV
500
being rigid and resistant to pressure, not easily scratched