CHEMICAL REACTIONS
What are the starting materials in a chemical reaction called?
Reactants
Define matter
Matter is anything that takes up space and has mass
Who created the periodic table?
Dmitri Mendeleev
Define a molecule
When two or more atoms bond together
True or False: Chemists only studies substances in laboratories.
False (Chemistry studies substances in all aspects of life.)
What do we call the substances formed as a result of a chemical reaction?
Products
What are the smallest particles of matter called?
Atoms
How are elements organised in the periodic table?
By atomic number and properties
Write the chemical formula for an oxygen molecule.
O2 (oxygen)
How many known elements are there?
118
Explain the structure of writing an element name and give an example.
Captial letter followed by lower case.
Example Cu, Mg
Define elements
Elements are pure substances that cannot be broken down into simpler substances.
What is the symbol for copper?
Cu
Define a compound
Two or more different bonded elements.
What is the charge of a proton
Positive
True or False: Chemical reactions only happen in laboratories.
False
(Chemical reactions occur constantly in living organisms.)
What three particles make up an atom
Protons, neutrons, and electrons
What do elements in the same column of the periodic table have in common?
Similar properties
Why are compounds important for living organisms?
Because they form the basis of cells and biological processes
What is the charge of an electron?
Negative
Write the formula for 2 hydrogen and 1 Sulfur
(Bonus 200 points - tell me the reactants and their charges)
H2S
Bonus - Reactants H+ + S2-
What determines the identity of an element?
(Bonus 100 - draw a labelled atomic structure)
The number of protons in its nucleus
(Check image contains nucleus with #p, #n, #e-)
What is the atomic number of Nitrogen and how number protons.
(Bonus 200 points for number of electrons)
Atomic number is 7, protons 7.
Number of electrons also 7.
Explain the conservation of mass
(Bonus 200: What is the conservation of energy)
The total mass of the reacting substances (the reactants) is equal to the total mass of the products of a chemical reaction.
Bonus - energy cannot be created or destroyed, only changed form.
Define physical and chemical change
Bonus 100 - what are the 3 chemicals that compose a sparkler?
Physical does not change its chemical composition.
Chemical formation of new chemical substances.
Bonus - pieces of metal (Al, Mg, Fe), slow burning gunpowder, sugar / starch, oxidizer in potassium nitrate or potassium chlorate