Pure Substances & Mixtures
Has no definite shape or volume
Gas
Atoms of the elements in the same group have what in common?
The same number of valence electrons in their outermost shell.
The nucleus contains these sub-atomic particles, which account for the atomic mass of an element. What is the charge of each particle?
Protons and Neutrons
What type of property is density? Calculate the following,
Physical Property
What does the Law of Conservation of Matter state?
Matter CANNOT be created or destroyed.
Has definite volume and takes the shape of the container
solid & liquid
Atom of the elements in the same period have what characteristic in common?
The same number of energy shells.
What type of matter are oxygen and helium at room temperature?
Gas
When something changes into another and cannot be put back to the original substance without chemical means
Chemical Change
25 grams
When ice cubes float in liquid water, is this considered pure substance or a mixture? Why?
pure substance, because the composition of the substance remains the same.
Which particle of the atom determines the identity of the element? What charge does this particle have?
A proton, positive
In which state of matter do particles vibrate but stay in fixed positions?
Solid
Combustibility, Flammability, Reactivity
Chemical Properties
How many atoms of each element are in
2C6H12O6
C = 12
H = 24
O = 12
The type of mixture that is also categorized as a solution; give 1 example of this mixture
Homogeneous Mixture, saltwater
Oxygen has 8 protons. Where would it be found in relation to nitrogen (7 protons) on the periodic table?
To the right of Nitrogen
What happens to the particles of substances when thermal energy is added?
The particles move faster and expand.
Color, Texture, Solubility, Phase Changes
Physical Properties
In a chemical reaction, the total mass of reactants is always equal to what?
The mass of the products
What are the two categories of pure substances? Give 1 example of each.
Elements(Oxygen) & Compounds(H2O-Water)
The smallest particle of matter that still has the characteristics of a specific element
Atom
Surrounding the nucleus in the cloud. What type of charge does this particle have?
Electron, negative
Mariana places a 33-gram piece of an unknown substance into a graduated cylinder that is filled with 20 mL of water, and the water rises from the 20 mL line to the 31 mL line. What is the density of the unknown substance in g/mL?
3.0 g/mL
What happens to the total mass when ice cubes melt in a beaker? What type of change is this?
The total mass stays the same and this is a physical change.