Lab Safety/
Scientific Method
Never Trust An Atom: They Make Up Everything
Solid, Liquid, or Gas?
Density
Physical or Chemical?
100
Which type of accident is the most common in the lab? a) fire b) broken glass c) chemical spills
b) broken glass
100
The smallest particle of a substance that retains the properties of that substance is called .......?
An atom
100
Which state of matter does the following sentence describe? "Atoms in an energy state so low that they maintain their shape"
Solid
100
What is the equation for density?
Density is equal to mass divided by volume. D=m/v
100
Which of the following describe PHYSICAL properties? Size; Boiling point; Color; Flammability; Luster (shine); Reacts with water (Select ALL that are true)
Size, color, luster
200
If you get chemicals in your eyes, how long should you eye wash for? a) 1 day b) 15 min c) 5 seconds
b) 15 min
200
What is an element?
An element is a pure substance that has a specific number of protons, neutrons, and electron and certain unique properties.
200
Flow, ability to change shape, malleability, conductivity, and solubility are all properties of which? Solids, Liquids, or Gases?
Solids
200
A substance has a mass of 12 g and a volume of 3 ml. What is its density? (MAKE SURE YOU INCLUDE UNITS IN YOUR ANSWER!)
The density is 4 g/ml
200
Which of the following describe a CHEMICAL change? Biting into an apple; Alcohol evaporating on your skin; Digesting an apple; Iron rusting; Ice melting (Select all that are true)
Digesting an apple, iron rusting
300
How should you smell chemicals? a) waft them toward you with your hand b) put your nose as close as possible c) don't ever smell the chemicals
a) waft with me, waft with me!
300
What is a molecule? Give an example of one.
A molecule is two or more elements that combine to form a new substance: H20 = Water; CO2 = Carbon Dioxide; NaCl = Salt
300
Cohesion, adhesion, and viscosity are words used to describe which state of matter?
Liquids
300
A substance has a density of 5 g/ml and its volume is 6 ml. What is its mass?
The mass is 30 g: 5 g/ml*6 ml=30 g
300
You blow dry your wet hair. Is this a physical or chemical change and why? Explain.
Physical change because you are changing state from liquid to solid.
400
Definitions: You need to answer both! If you do not follow the safety rules of the lab, you put yourself at ____ of injury. There are things in the lab, including various apparatus, that could potentially be dangerous or a _______.
Risk Hazard
400
On a periodic table, the atomic number of an element tells how many protons is has. Which element has 8 protons?
Oxygen
400
In your own words, explain the difference between hardness and strength in solids.
Hardness: Hardness is a measure of how easy it is to scratch a solid – it is not the same as strength. Slate and concrete are very strong solids, but are easily scratched so they are not as hard. -------------- Strength: Strength is the ability of a solid to withstand a force. Metals are generally very strong, but waxy solids are easily squashed.
400
In your own words, explain what density is. (Hint: think about what volume means and what mass means).
Volume is how much space something takes up. Density means how much mass something has per the volume (space) it occupies, or how densely packed (concentrated) the particles of a substance are relative to its size.
400
I put food coloring into a cake I am making and the batter changes color. This is a _________ change. I then bake the cake and it was a delicious __________ change.
Physical, chemical.
500
Explain the steps of the Scientific Method.
Make an observation; Ask a question; Form a hypothesis & make a prediction; Do a test or experimentation; Analyze data and draw a conclusion; Share results.
500
The name "atom" comes from the Ancient Greek word meaning "indivisible" or not capable of being divided. Explain, in your own words, why scientists called these particles "atoms".
Because an atom is the smallest part of a substance that still maintains the properties of that substance and cannot be broken down further.
500
What is Brownian Motion? (Hint: it has to do with movement of particles in liquids and gases!)
The random movement of microscopic particles suspended in a liquid or gas, caused by collisions between these particles and the molecules of the liquid or gas.
500
Explain the displacement method and when you should use it.
Displacement is used to calculate the volume of an unusual solid by dropping the solid into a known amount of water and calculating the amount of water displaced through subtraction.
500
A metal is placed in water. Soon, there is a new color that is visible. Is this a physical change or chemical change? What other indication could help you decide?
It is likely chemical: a change in odor, or if it burns would clarify it.
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