Science Ultimate Challenge Flashcards
What is a pure substance?
A substance that is the same throughout the sample. For example, a bowl full of table salt (Sodium chloride) is a pure substance, but as soon as you mix something else with it, its a mixture/compound.
What is the difference between physical and chemical changes?
Physical changes are temporary and can be reversed, but chemical changes cannot be reversed.EXAMPLES: Water freezing is a physical change. Popcorn popping is a chemical change.
When a solid changed to a gas, it is called _________.
Sublimation
Neutrons have ______ charge.Electrons have a _______ charge.Protons have a ______ charge.
No chargeNegativePositive
Where are each of these particles located within the atom?ProtonsNeutronsElectrons
Protons are inside the nucleus of the atom.So are the neutrons.Electrons orbit the nucleus of the atom.
What are some properties of chemicals?
Is/does it…Radioactive Flammable Produce gas Change colour Conduct heat etc…
The elements to the far right of the periodic table are called…?
Noble gases
The elements to the far left of the periodic table are called…?
Alkali Metals
The elements to the right of the alkali metals are called…?
Alkaline earth metals
The elements in the middle of the periodic table are called…?
Transition metals
What are qualitative and quantitative properties of stuff?
Qualitative properties deal with descriptions that cannot be measured.EXAMPLES: Colour, texture, smell, taste…Quantitative properties deal with numbers and things that can be measured.EXAMPLES: Length, area, volume, height…
How would you draw a BR (Bohr-Rutherford) diagram model of an oxygen atom?Hint: Oxygen has an atomic number of 8 and has an atomic mass of 16
The atomic number tells you how many electrons there are, AND how many protons are in the nucleus.Since you know there are 8 protons, you would subtract that number from the atomic mass to find the number of neutrons. In this case:16 - 8 = 8 neutrons in the nucleusTo draw the diagram, you would write the number of protons and neutrons in the nucleus as this:P 8N 8Then, draw the electrons orbiting the nucleus. The first shell has 2, the second one has 8, third has 8, and so on.
What are the rules for drawing the electrons in their shells on BR diagrams?
The first shell always contains only 2 electrons. They are both at the top.The second shell has 8, and they go NORTH, SOUTH, EAST, then WEST.+The third shell has the same rules as the second one, and so on.
How many protons, neutrons, and electrons does the following element have:Silicon (Si)A# - 14AM - 28
Electrons - 14Protons - 14Neutrons - AM - A#28 - 14= 14
How many protons, neutrons, and electrons does the following element have:Bromine (Br)A# - 35AM - 80
Electrons - 35Protons - 35Neutrons - AM - A#80 - 35= 45
What is the difference between a heterogenous and homogenous mixture?
A heterogenous mixture is a mixture in which you can see the different substances, while in a homogenous mixture you cannot identify the different substance by sight.
What is the difference between a suspension and solution?
A solution is a complete mixture of two compounds, and a suspension is tiny particles of one compound inside another.
Mixture can be separated by?
physical and mechanical methods.
What is the difference between a pure substance and a mixture?
A pure substance has a constant composition.
What are the two categories of pure substance?
Elements and compounds.
What is the difference between an element and a compound?
An element is one kind of atom, and cannot be broken down into further particles. A compound is two or more types of atom, and is always the same ratio.
What is the particle theory of matter?
The theory that everything is made up of small particles, called atoms.
What are physical properties?
Properties that can be identified without changing a substance’s composition.
What are chemical properties?
Properties that have to do with reactions, such as:Reaction with waterReaction with oxygenReaction with acidToxic (reacts with organism)Radioactive (nuclear reaction)Combustible
What are some physical properties of matter?
ColorTextureOdourLustre (shiny-dull)Clarity (opaque-transparent)TasteState of matterMelting and boiling pointsCrystal form (texture -> powder, definite shape)ViscosityHardness (Resistance)pH (Acidic-Basic)
The safety symbol shapes mean?
Octagon - dangerDiamond - warningTriangle - caution
All hazardous products must have labels. The information on the product can be found on the?
MSDS, or Material Safety Date Sheet.
What are the WHMIS symbols?
Compressed gas (bottle)Flammable (flame)Oxidizer (fire on circle)Poisonous (skull/crossbones)Toxic (Capital T)Biohazard (circles)Corrosive (burning drip on hand and table)Reactive (Capital R with test tube)
What is a triboelectric series?
A chart that shows different materials.The higher a material is on the series, the greater its tendency to lose electrons
Name three good conductors
CopperAluminumIronMercuryOther minerals
Name three good insulators
RubberWoodPlasticPure water
Name three FAIR conductors
Water with mineralsMoist airHuman bodyCarbonSoil
What does the law of attraction state?
Opposites attract, and same charge repel.Negative —> Positive
In a series circuit, what happens when you double the load?
Double the load, HALF THE CURRENT.For example, if a series circuit has a current of 0.30 C/s with one light bulb, when you add another light bulb it will be 0.15C/s
What is Kirkoff’s law for a series circuit?(Current and voltage)
The current is the same throughout the circuit, no matter where you measure it.I=I=I=I=I…The total voltage is obtained by adding all the voltage drops in the circuit.Total voltage = V+V+V+V+V…
What does kirkoff’s law state for parallel circuits?
The voltage is the same throughout the circuit, no matter where you measure it.V=V=V=V=V…The total current is obtained by adding all the current drops in the circuit.Total current = I+I+I+I+I+I…
What is the formula for finding the voltage is a circuit?
V = IR
A skull and crossbones in an octagon means…
Danger, a great risk of poisioning
How do you charge something by contact?
Charging by contact occurs when electrons are transferred from the charged object to the neutral object that it touches.
Define ‘power’ in electricity
Power is the amount of energy used per second.
What particle is transferred to create electricity?
Electrons.
How does friction affect electrons?
It can transfer them from one element to another depending on their places in the triboelectric series.
What’s the term used to explain the triboelectric series?
Electron affinity.
How do charges behave?
Opposites attract, like charges repel.
When is water an insulator?
When it is pure. Otherwise dissolved minerals act as conductors.
How can you detect static charge?
Using an electroscope, or a pith ball.