Periodic Table
The first element of the Periodic Table
What is Hydrogen
Matter is not created nor destroyed it is conserved
What is the Law of Conservation of Mass
The number of Hydrogen atoms in a molecule of water
What is the number 2
Chemists change these numbers placed in front of chemical formulas to balance an equation without changing the substances themselves.
What are coefficients
This variable is the one that the scientist deliberately changes or manipulates in an experiment.
What is the independent variable.
There are 7 of these in the periodic table
What are periods
In a chemical reaction the arrow generally means what is happening
What is the yield
If 10 grams of Reactant A completely reacts with 15 grams of Reactant B, this is the total mass of the resulting products.
What is 25grams of product
Changing these small numbers at the bottom right of a chemical symbol is strictly forbidden when balancing equations because it changes the substance's identity.
What are subscripts
This variable is the observed result or the data being measured in response to a change.
What is the dependent variable.
There are 18 of them in the periodic table
What are groups
The chemcials generally shown on the left side of the arrow
What are the reactants
50-gram log is burned completely, leaving behind 5 grams of ash. The remaining 45 grams of mass escaped into the air in this state of matter.
What is a gas
This is the missing coefficient needed to balance this equation: N2 + 3H2 --> _____ NH3
What is the number 2
When plotting experimental data on a standard line graph, this axis is where the independent variable belongs.
What is the x axis.
The man who is credited with devising the modern periodic table.
Who was Dimitri Mendeleev
In any chemical reaction, the total mass of the reactants must always equal the total mass of these.
What are the products
In the reaction (2H2 + O2 --> 2H2O), if 4 grams of hydrogen react completely with 32 grams of oxygen, this many grams of water are formed.
What is 36 grams
To satisfy the conservation of mass, the unbalanced equation CH4 + O2 --> CO2 + H2O requires this coefficient in front of both O2 and H2O.
What is the number 2
If a technician tests three different brands of batteries in the exact same flashlight to see which lasts longest, the battery brand is this variable.
What is the independent variable
his element is the basis for all organic chemistry and known life on Earth.
What is Carbon.
To accurately prove this law in a lab setting, experiments must be conducted in this specific type of system where no matter can escape.
What is a closed system
A scientist mixes 12 grams of carbon with an unknown amount of oxygen to produce 44 grams of carbon dioxide. This was the mass of the oxygen used.
What is 32 grams
This is the fully balanced form of the synthesis reaction where aluminum reacts with oxygen gas:
Al + O2 --> Al2O3
What is 4Al + 3O2 --> 2Al2O3
The parts of the expereiment that do not change from one experiment to the other
What are the controls