Particle Diagrams
What are the features you must include in a particle diagram for a gas, and what do they mean?
Long arrows = lots of movement
Drawn far apart = lots of space between particles,
Squiggly line = a little vibration
Which state of matter has the greatest amount of space between its particles?
Gas
How do you classify a bag of chex-mix?
Mixture, heterogenous
A change in the state of matter is an example of what type of change?
Physical change
In a density column, the cooking oil is layered above the water.
An ice cube rests at the top of the water, and at the bottom of the oil.
Describe the ice cube's density compared to both the water and the oil.
The ice cube has a greater density than the cooking oil, but a smaller density than the water.
Draw a particle diagram of ice melting into water. Include all proper labels and features.
solid to liquid
vibrations and no space in the solid
little bit of movement, more space, and vibrations in liquid
As a substance freezes, what happens to the particle energy and movement?
They both decrease
How do you classify sugar ( C12H22O11 )?
Pure substance, compound
A change in the identity of a substance is the requirement for what type of change?
Chemical change
A liquid has a mass of 56.43 grams and a volume of 34.7 mL. What is the density of the liquid?
1.63 g/mL
Draw a particle diagram of a sample of a pure substance, that is also an element, AND can be classified as a molecule.
Two particles that are the SAME, touching together in a diagram.
What phase change occurs when a gas turns directly into a solid?
Deposition
How do you classify sodium (N2)?
Pure substance, element
Crushing a smartie into powder is an example of what type of change?
Physical change
The density of ice is 0.917 g/cm3. What volume of ice (in cm3) does 21 grams of ice occupy?
23 cm3
Draw a particle diagram of a sample of bronze (made of copper and tin – aka Cu and Sn). Include a key for your diagram.
Two particles, that are DIFFERENT (with a key labeling them), NOT touching in the diagram.
What phase change is occurring when you smell a flower?
Sublimation
How do you classify water?
Pure substance, compound
Baking, eating, and digesting a cake are all examples of what type of change?
Chemical change
A student weighs an unknown sample and determines the mass is 12.51 grams.
They then add 25.5 mL of water into a graduated cylinder, place the sample in it, and notice that the water level rises to the 32.0 mL mark.
What is the density of this unknown sample, in g/mL?
1.92 g/mL
Draw a particle diagram containing a mixture of 2 different elements and 1 compound. You do not need to specify which elements or compounds they are, and you do not need to make a key, but you do need to make it clear through your diagram that the sample is a mixture of elements and compounds.
Answer varies :)
Need two different particles, not touching each other, and one particle with multiple different touching particles.
There are water droplets forming on the outside of your cold water bottle as it sits out in the hot sun. What phase change is occurring, and what are the initial and final states for this phase change?
Condensation is occurring
Initial state = gas
final state = liquid
How do you classify stainless steel (made of iron, carbon, and manganese – aka Fe, C, and Mn)?
Mixture, homogenous
Density is an example of what type of property (be specific!)? Why is this important?
Density is an example of an intensive property, which is important because it does not rely on the amount of matter, and will remain the same for all samples of the same identity (under the same conditions).
This lets us use density to identify unknown substances.
A sample of an unknown substance has been found to have a density of 4.630 g/mL, and a mass of 2.86 kilograms (kg).
Calculate the volume of the sample in meters cubed (m3).
0.618 m3