Chemistry 151 Exam 1 ACTUAL UPDATED QUESTIONS AND CORRECT ANSWERS
Define Chemistry The study of properties of materials and the changes they undergo.
Define Matter Anything that has a mass & occupies space
Name the states of matter Solid, liquid & gas.
, Name the 3 compositions of matter Element, compound or mixture.
Define & describe a Solid Matter composed of particles that are packed closley together.
Name an example Has a fixed shape & volume.
Example: rock
Define and describe a liquid Matter composed of particles that are packed closer together than in a gas, move
Name an example at high speeds and collide often.
Has a fixed volume, but no shape.
Example: water
Define & describe a gas Matter composed of particles that are far apart from each other, move at high
Name an example speeds and collide often.
Has no fixed shape or volume; conforms to the shape of the container is it placed
in.
Example: O2 and N2
What is a pure substance? Matter with fixed composition's and distinct proportions.
What are the 3 categories of pure substances Elements, compounds & mixtures
What is an element? A substance that cannot be broken down into a simpler substance.
Example: H, hydrogen; S, Sulfur; Ag, Silver; Pb, Lead.
What is a compound? A substance with two or more elements chemically combined.
True or false: The ratio of the element in a specific True.
compound is always constant? Example: H2O, 11% H and 89% O
True/false: compounds can be separated by chemical True.
methods?
Define a mixture. A substance that consists of 2 or more substances physically combined.
T/F: The ratio of the substance in a mixtures varies? True
Name two types of mixtures Homogeneous & heterogeneous mixture
What is the difference between a homogeneous & Homogeneous mixtures is a mixture with a uniform composition whereas a
heterogeneous mixture? heterogeneous mixture has an inconsistent composition.
T/F: In a mixture each substance does not retain its False. Each substance does retain its chemical identity.
chemical identity.
Define a physical change. Change in physical appearance, but the chemical identity remains the same.
Name an example Example: boiling water; H2O (liq.) -->H2O (gas.) steam
vise-versa; H2O (liq.) --> ice (solid) freezing
Define Chemistry The study of properties of materials and the changes they undergo.
Define Matter Anything that has a mass & occupies space
Name the states of matter Solid, liquid & gas.
, Name the 3 compositions of matter Element, compound or mixture.
Define & describe a Solid Matter composed of particles that are packed closley together.
Name an example Has a fixed shape & volume.
Example: rock
Define and describe a liquid Matter composed of particles that are packed closer together than in a gas, move
Name an example at high speeds and collide often.
Has a fixed volume, but no shape.
Example: water
Define & describe a gas Matter composed of particles that are far apart from each other, move at high
Name an example speeds and collide often.
Has no fixed shape or volume; conforms to the shape of the container is it placed
in.
Example: O2 and N2
What is a pure substance? Matter with fixed composition's and distinct proportions.
What are the 3 categories of pure substances Elements, compounds & mixtures
What is an element? A substance that cannot be broken down into a simpler substance.
Example: H, hydrogen; S, Sulfur; Ag, Silver; Pb, Lead.
What is a compound? A substance with two or more elements chemically combined.
True or false: The ratio of the element in a specific True.
compound is always constant? Example: H2O, 11% H and 89% O
True/false: compounds can be separated by chemical True.
methods?
Define a mixture. A substance that consists of 2 or more substances physically combined.
T/F: The ratio of the substance in a mixtures varies? True
Name two types of mixtures Homogeneous & heterogeneous mixture
What is the difference between a homogeneous & Homogeneous mixtures is a mixture with a uniform composition whereas a
heterogeneous mixture? heterogeneous mixture has an inconsistent composition.
T/F: In a mixture each substance does not retain its False. Each substance does retain its chemical identity.
chemical identity.
Define a physical change. Change in physical appearance, but the chemical identity remains the same.
Name an example Example: boiling water; H2O (liq.) -->H2O (gas.) steam
vise-versa; H2O (liq.) --> ice (solid) freezing
