States of Matter
This state of matter has a definite shape and a definite volume.
Solid
Density compares how ____ molecules are packed in a object or substance
Tightly
Used to classify elements as a metal, nonmetal, metalloid, or rare-earth element
Periodic Table
If something is made of only one type of particle and melts at one exact temperature, we call it a _____.
Pure Substance
A chemical change occurs when _____ or more substances chemically combine to create a new substance with different _________.
two, properties
The state of matter where particles move freely, fill their container, and have no definite shape.
Gas
Defined as the amount of space an object takes up
Volume
This type of element is shiny, conducts heat and electricity well, and is used to make wires and coins.
Metal
This mixture has parts you can see or pick out, like a salad or sandy water. What is it?
Heterogeneous Mixture
Bubbles form when vinegar and baking soda mix. Which type of evidence does this show for a chemical change?
Production of a gas
The “stuff” that all objects and substances in the universe are made of.
Matter
Two liquids don’t mix and form layers in a test tube. The top layer is oil and the bottom layer is syrup. Which liquid is more dense?
Syrup
This element is dull, brittle, does not conduct electricity, and is used in pencils and as a lubricant. Classify it.
Nonmetal
When a mixture is clear and uniform and the particles are spread evenly so you can’t see them, we often call it a ____ or a _____.
Homogeneous mixture or solution
After mixing two clear solutions, a cloudy solid falls out. What is this solid called and what does it indicate?
Production of precipitate
Two or more atoms that are held together by chemical forces is a
Molecule
Explain why a small wooden block floats on freshwater but sinks when placed in saltwater
Saltwater is more dense than freshwater because dissolved salt increases mass per volume. The block floats in freshwater because the block’s density is less than freshwater, but in saltwater the fluid’s density becomes greater than the block’s, so the block sinks
Classify this element based on its properties. This element is used in computer chips because it can conduct electricity under some conditions.
Metalloid
Is steel and brass a pure substance, homogeneous mixture, or a heterogeneous mixture?
Homogeneous Mixture
You touch a container after a reaction and it feels warm. What type of evidence is this and what does it suggest happened?
Change in thermal energy
Describe what happens to particle arrangement and motion when a liquid is heated enough to become a gas
Particles move faster, spread farther apart, and overcome the attractions that held them in the liquid, so they move independently and fill the container (become a gas).
The density of water is
1.0 g/cm3
They are called "rare" because they are difficult to mine from the Earth.
rare-earth elements
List 3 physical properties
Density, Melting and Boiling point, Color, Luster, Hardness, Malleability, Ductility, Conductivity, Solubility, Odor
A student mixes two solutions and observes a pale green solution turn deep blue with no bubbles and no temperature change. Which evidence supports a chemical change and why?
Color change supports a chemical change because it indicates formation of a new substance with different properties.