Elements, Compounds and Mixtures
Periodic Table
Physical vs Chemical
Chemical Reactions
Conservation of Mass
100
What does the atomic number always stand for?
The # of protons in an element
100
How is the periodic table arranged?
The periodic table is arranged by increasing atomic number
100
What is the formula for density and how do you know if an object will sink or float?
The formula is Mass/Volume. If an object's density is less than 1 it will float, if it is greater than 1 it will sink
100
What do you call the substances that you get out of a chemical reaction?
Products
100
K + AgCl → KCl + Ag Is this equation balanced?
Yes
200
How do you find the # of Neutrons in an element?
You have the subtract the Mass Number - the atomic number
200
Finish this: Groups and Families.......
Groups and Families, Valence electrons Rows and Periods- shells!
200
What is the difference between a property and a change?
A property describes the characteristics of an object and a change tells the action that is taking place.
200
What do we call the substances that you put into a reaction?
Reactants
200
Is this equation balanced? H2O2 → H2O + O2
No- There is one more Oxygen in the product
300
Name the 2 types of pure substances:
Compounds and Elements
300
Which Group is not reactive and explain why:
The Noble Gases, Group 8, is unreactive because they have a full shell.
300
Explain what a solute and solvent are in a solution:
A solute is what you mix into the solvent to form a solution.
300
How do we know how many molecules are in a chemical formula?
The Coefficient
300
If the mass of the products is lower than that of the reactants, what probably happened?
A gas was released
400
Give the 2 types of mixtures, explain what they are and give an example:
Homogeneous and Heterogeneous Mixtures. Homogeneous mixtures are the same throughout, heterogeneous are not uniform throughout. Examples may vary...
400
Give the 3 main sections of the periodic table and a characteristic of each.
Metals are malleable, ductile, good conductors, and solid at room temperature. Metalloids are semi-conductors, Non metals are good insulators and mostly gases at room temp.
400
Give the definition of a physical change and chemical change and give an example.
A physical change, is a change to the size, form or state of matter of an object without changing it's chemical composition. A chemical change is when a new substance if formed after a chemical reaction takes place.
400
How do we know how many of each element is in a chemical formula?
Count the subscripts
400
What type of system does it have to be in order for the law of conservation of mass to be true?
A closed system
500
Give 3 ways in which compounds and mixtures are different
Compounds combine chemically, mixtures combine physically. Elements lose their properties when forming compounds, elements keep their properties when forming mixtures. Compounds are pure substances, mixtures are not.
500
Which two groups are highly reactive and explain why:
Group 1 and Group 7 because they both are only 1 valence electron away from a full shell.
500
Give 4 signs of a chemical change
Temperature change, light released, bubbling (gas released) , precipitate forming, cooking, combustion
500
2 NaCl + CaO → Na2O + CaCl2
How many of each element are in the reactant?
500
What does the Law of Conservation of Mass state?
The mass of the reactants always equals the mass of the reactants
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