States of Matter
This state of matter has a definite shape and a definite volume.
Solid
This is the simplest form of matter and contains only one type of atom.
Element
This is the amount of space and object takes up and it can be measured with a graduated cylinder.
Volume
An object has a mass of 20 g and a volume of 5 cm³. What is its density?
4 g/cm3
When ice changes from a solid to a liquid, what phase change is occurring?
Melting
In this state of matter, particles are spread apart and move freely throughout their container.
Water, H₂O, is made of hydrogen and oxygen that are chemically combined. What type of matter is water?
Compound
This physical property describes the amount of matter per unit volume of a substance and helps when determining whether a substance will sink or float.
Density
How could you calculate mass if you know the volume and density of a substance?
Mass = Density x Volume
A piece of iron develops a reddish-brown coating after being exposed to oxygen and moisture. Is this a physical or chemical change? What evidence supports your answer?
A chemical change because rusting forms a new substance that appears a different color.
As the temperature of a substance increases, what happens to the average kinetic energy and motion of its particles?
Both increase together
Salt water looks the same throughout, and you cannot distinguish the different substances in it. What classification of matter is this considered?
Homogeneous mixture or solution
Describing a copper wire as being flexible and having the ability to be bent into different shapes is an example of a ______________ property.
A graduated cylinder contains 16 mL of water. After an irregular object is placed in it, the water level rises to 22 mL. What is this method called and what is the volume of the object?
Displacement; 6 mL
A solid steel bar is melted down. The initial temperature measured to be 1,200° C and once melted the molten steel's temperature increased to 1,650° C. What type of change occurred and what is your reasoning?
A physical change because no new substance is formed, only a change of state occurred.
A drop of food coloring spreads throughout a beaker of warm water faster than it does in cold water. What process is occurring, and why is it faster in warm water?
Diffusion occurs faster in warm water because the particles have more kinetic energy and move faster in the warm water.
A student has a mixture containing rocks, sand, and water. The different components can be seen separately. What classification of matter is this considered?
Heterogeneous mixture
A metal is heated. Its mass stays the same, but its volume increases. What happens to its density, and why?
Its density decreases because density is mass divided by volume. If mass stays the same while volume increases, density decreases.
A metal object has a mass of 21.91 g. Water in a graduated cylinder rises from 24.50 mL to 26.95 mL when the object is added. What is the density?
8.94 g/mL
A student mixes two substances. The mixture becomes hot, bubbles form, and a solid material appears at the bottom of the beaker. What type of change most likely occurred, and identify three pieces of evidence supporting your answer.
A chemical change. Evidence includes temperature change, gas production/bubbling, and formation of a precipitate.
A substance is being heated. A graph shows its temperature stays constant for several minutes even though heat is still being added. What is happening to the substance?
It is undergoing a phase change. The added energy is being used to change the state of matter rather than increase its temperature.
Classify each substance: Carbon (C), tap water, sugar, carbon dioxide (CO₂), gumbo, and coffee
element
homogeneous mixture
compound
compound
heterogeneous mixture
homogeneous mixture
Identify the following as physical or chemical properties:
1. Hydrogen gas catches fire if exposed to a flame.
2. Vinegar produces bubbles of gas when reacted with baking soda
3. A steel nail has a density of 7.85 g/cm3
4. The boiling point of water is 100° C
1. chemical
2. chemical
3. physical
4. physical
Object A has a mass of 22.3 g and a volume of 10.8 cm³. Object B also has a mass of 22.3 g but a volume of 12.5 cm³. Without calculating, which object has the lesser density?
Object B, density decreases when volume is increased.
A student notices water droplets around their cold glass and says water is leaking through. What is actually occurring?
Condensation occurs when the water vapor in the air surrounding the glass is cooled down to liquid form.