Midterm 8th Grade Flashcards
What four pieces of key information about an element are found in a single cell of the periodic table? What does each signify?
Element name - the name of element
Element symbol - abbreviation
Atomic number - number of protons
Atomic mass - average of all isotopes
What are the rows and columns of a periodic table called?
Rows are called periods, and columns are called groups or families
What are the three subatomic particles in an atom?
Protons, neutrons, and electrons
What are the three major classes of elements?
Metals, nonmetals, and metalloids
What are valence electrons and why are they important to know? What is the maximum number of valence electrons that an element can have?
Valence electrons are the electrons on the outermost electron shell of an atom. They determine the reactivity of an element. There can be up to 8 valence electrons on an atom
What are the differences between ionic bonds and covalent bonds?
Ionic bonds transfer electrons; covalent bonds share electrons. Ionic bonds are harder to break than covalent bonds. Ionic bonds form between metals and nonmetals; covalent bonds form between nonmetals and nonmetals
What is the difference between polar and nonpolar bonds?
Both are covalent bonds, but polar bonds have a slight positive and negative charge
What are the three types of chemical reactions?
Synthesis, Decomposition, and Replacement
What are the three possible signs that a chemical reaction has occurred?
Color change, Gas production, Formation of a precipitate
What is the difference between an exothermic and an endothermic reaction?
Exothermic reactions produce more energy than was required for the reaction, and endothermic reactions absorb more energy than is released
What are the different parts of the chemical equation?
Reactant, yield arrow, product, coefficient, subscript
What is a reactant?
Reactants are the elements or compounds that are put into a chemical reaction, and they appear on the left side of the equation.
What is a yield arrow?
The yield arrow shows that a chemical reaction occurred.
What is a product?
The products are the elements or compounds that result from a chemical reaction, and they appear on the right side of the equation..
What is a coefficient?
A coefficient is a large number that appears in front of an element or compound, showing how much of that element or compound is present in the equation.
What is a subscript?
A subscript is a small number that appears after an atomic symbol, showing how much of a particular element is present in a compound.
What are the factors that could change the speed of a chemical reaction?
Surface area, temperature, concentration, and the presence of a catalyst or inhibitor
What is a synthetic material? What is the most common synthetic material?
A man-made material, the most common being plastic
What is a monomer and a polymer?
Monomer - a compound that be repeated many times in a chain
Polymer - a long chain of compounds made up of repeating monomers
Define motion
Motion - the position of an object changes compared to another object
Define reference point
Reference point - an object used for comparison to determine if another object is moving
Define force
Force - a push or pull
Define speed
Speed - the distance an object travels per unit of time
Define velocity
Velocity - the speed of an object traveling in a particular direction
