Systems of Linear Equations
x + y = 7
- x - y = 12
No point of intersection (UNDEFINED)
The periodic table has 7 ________ and 18 _________.
periods and groups/families
Write an equation in standard form given that m = 1/3 and the y-intercept is at (0, 5).
- x + 3y = 15
Balance the reaction and determine the type of chemical reaction.
Na2S + CaCl2 yields CaS + NaCl
Na2S + CaCl2 yields CaS + 2NaCl
Double Replacement
Electrons in the outermost energy shell of an atom are called _________ electrons.
Valence
x + y = 4.5
- 2x + 4y = 6
(2, 2.5)
This element is in group 13 and has 66 neutrons.
Indium
Write an equation in slope-intercept form given the points (-4, -3) and (2, 9).
y = 2x + 5
CH4 + 2O2 yields CO2 + H2O
What are the reactants and what are the products?
Reactants = CH4 and 2O2
Products = CO2 and H2O
The starting materials of a chemical reaction are called ___________, and the substances formed are called _____________.
reactants and products
2x - 3y = 5
- 3x + 4y = - 8
(4, 1)
How many molecules of CO2 are in 264 grams of CO2?
6
Write an equation in standard form given the points (0, -3) and (2, -2).
- x + 2y = -6
Balance the equation.
CO2 + H2O yields C6H12O6 + O2
6CO2 + 6H2O yields C6H12O6 + 6O2
Changes of states (solid, liquid, gas) are considered ___________ change.
physical
4x + 3y = 18
4x = 8 + 2y
(3, 2)
What is the mass of three NH3 molecules? What type of compound is NH3?
51 grams; covalent compound
Write the equation of the line in slope-intercept form that passes through (4, 2) and is parallel to the line y = -3/4 x - 5.
y = -3/4 x + 5
6CO2 + 6H2O yields C6H12O6 + 6O2
C6H12O6 + 6O2 yields 6CO2 + 6H2O
Name one of the two chemical reactions above.
Photosynthesis and Cellular Respiration
Atoms that have either given up or taken in electrons have positive or negative charges. They are called _______.
ions
0.5x + y = 0
x - y = -15
(0, 15)
Name 3 elements that are in liquid state at room temperature.
Bromine, Gallium, Mercury, Cesium, Francium
y = 3x + 7
Balance the equation.
C2H6 + O2 yields CO2 + H2O
2C2H6 + 7O2 yields 4CO2 + 6H2O
Group 15 is also called the Nitrogen family, and group 16 is called the Oxygen family. What are groups 17 and 18 called?
Halogens and Noble Gases