Unit 1- Chemistry Flashcards
What are elements?
Pure substance that cannot be broken down into a simpler substance. Eg. Carbon, oxygen, and iron
What is a compound?
Pure substance made from two or more elements that are combined together chemically. Eg. Water, salt and ammonia.
What are physical properties?
Characteristics of a substance that can be observed or measured. Eg. Texture ( fine, course, powder, granular)
Odour (sweet, sour, acrid, smoky)
Malleability ( hammered into sheets)
What is a chemical property?
Ability of a substance to change into a new substance or substances. Eg. Flammability, toxicity and corrosion
What is matter?
Matter is anything that has mass and takes up space. Matter makes up everything around us.
What are the 5 particle theory of matter?
- All matter is made up of extremely tiny particles.
- Each pure substance is made up of its own kind of particle, different from other pure substances.
- Particles attract each other.
- Particles are always moving.
- Particles at high temperatures move faster on average than particles at low temperatures.
What would the solid state look like?
Molecules are “stuck” together.
Molecules are vibrating back and forth but are keeping their positions.
They have their lowest energy when they are in the solid state.
Their shape does not change when the container is tilted.
What does the liquid state look like?
Molecules are spread out slightly but touching.
They are vibrating back and forth faster than when in the solid state and they are moving past one another.
Higher energy than in the solid state.
They take the shape of the bottom of the container and have a horizontal top surface.
They can be poured.
What does the gas state look like?
Molecules are far apart and flying around colliding with each other and the walls of the container.
Molecules are moving fastest and with highest energy when in the gas state.
They spread out to take the shape of the entire container.
They can be poured.
What is a pure substance?
Its a homogenous composition and is the same throughout.
What is an element?
An element is made up of one type of particle/atom and can’t be broken down further. Eg. Gold, oxygen and mercury.
What is a mixture?
It has at least 2 kinds of particles or substances and it can be mechanically separated into pure substances.
What is a solution?
Homogeneous composition Particles are uniformly scattered Can't see different parts (particles too small to see) Transparent (can see through it) Composed of a solvent and a solute
What is an mechanical mixture?
It’s a heterogeneous composition, not uniform throughout and usually can see different parts/components
What is a suspension?
Particles can be seen with the naked eye or a low power microscope and gravity will cause the suspended particles to separate over time.
What is an ordinary mechanical mixture?
Different components are large enough to see with the naked eye.
What is colloids?
Homogeneous in appearance Tiny particles that can't be seen with a microscope Particles won't settle May show Tyndall effect Usually opaque
What is qualitative?
Is a description of the substance or change that is not measured. Eg. Blue, granular, dissolved, reacted
What is Quantitative?
Is a description of the substance or change that is measured and involves a value. Eg. B.P. Is 10 C, mass= 113g
What is a physical change?
A change that does not result in a new chemical substance being formed. Changes may be reversed. Eg. All changes of state, changing the shape or size of the substance, dissolving the substance
What is a chemical change?
Results in a new substance being formed that has different properties.
Look for’s: hard or impossible o reverse, colour change, heat or light given off or absorbed, starting substance used up, bubbles form in a liquid, precipitate forms in liquids. Eg. Cooking, burning, corroding and reacting
What is an atom?
Smallest part of an element that has all of the element’s properties. Eg. Atoms of copper are not the same as atoms of iron.
Classify sugar and water
It’s a solution because you can’t really see the sugar particles with a naked eye and the sugar is transparent.
Classify beach sand.
It’s an ordinary mechanical mixture because you can see all the different parts with your naked eye.
Classify gold.
Gold is an element because it’s made up of only one type of atom, and it can’t be broken down any Further.
Classify water.
It’s a compound because it’s 2 or more elements that are chemically combined indefinite proportions and can be broken down.
What is an independent variable?
The one that is changed.
What is an dependant variable?
What we focus on to see if it’s affected.
What is an controlled variable?
The variable that doesn’t change.
How is the periodic table organized?
The periodic table is organized by... Rows/families/columns Going downward the atomic number increases The chemical and physical properties Atomic mass
What is the element found at group 13 period 3?
Aluminum
What is the period and group for zirconium?
Period 5 group 4
What are the characteristics of a neutron?
No charge
The mass is 1
Are located all around the nucleus.
What are the characteristics of a proton?
Positive charge
Mass of 1
And located in the nucleus
What are the characteristics of an electron?
Negative charge
Mass of 0
Located outside the nucleus
Determine the atomic structure for barium. *draw it
Barium
107
Bh P-107
272 E-107
N-165Determine the atomic structure for antimony *draw it
Antimony
51
Sb P=51
122 E=51
N= 71Determine the atomic structure for sulfur *draw it
Sulfur
16
S P=16
32 E=16
N=26List the key properties of alkali metals?
All these metals are sliver and grey in colour.
They conduct electricity and heat.
Have low melting points( all melt below 170 degree)
Soft
Moving from top to bottom there is a regular increase in density.
List the key properties of halogens?
Elements are all non-metals. Noticeable colour. With slight heating they form gases Very reactive From bottom to top the colours of the Halogens grown in intensity.
List the key properties of alkaline earth metals.
Shiny Silvery-white Somewhat reactive metals at standard temperature and pressure. Low densities. Low melting points. Low boiling points.
Key properties of noble gases.
Naturally colourless.
None of the gases are chemically reactive.
The density of the gases increase staidly.
What are elements named after?
Scientist Mythology Planets Places Properties
Based on the properties elements can be divided into what 3 groups?
Metals
Non-metals
Metalloids
What is an atomic number?
Number of protons and electrons in an atom.
What is the atomic mass?
Average mass of one atom of the element.
What is the atomic number?
It’s the rounded atomic mass.
How to find the number of neutrons in an element?
neutrons = mass# - atm
Find the number of neutrons for Mercury.
Protons =80
Electrons = 80
Neutrons =201-80=121
What is the relationship between the number of valence electrons and the group number?
The valence electrons number is equal to the group number.
Hydrogen is a non-metal. Why is it not found with the other non-metals on the right side of the periodic table?
Because it has 1 valence electron so it belongs with all the other elements that have one valence electron. Similar reactivity.
Why is helium not found in group 2 when it only has 2 valence electrons?
Helium isn’t placed in group 2 because is valence shell is full. Also heliums properties are similar to the other elements with a full shell.
How do you think the number of valence electrons will impact the physical and chemical properties of an element or groups of an element?
Elements with full shells (noble gases) are unreactive
The fewer the number of valence electrons that an atom has to gain or lose the more reactive it is.
What are the 5 bonding rules?
- Metal atoms react by losing valence electrons until their outer-most energy level is ‘empty’
- Non-metal atom react by gaining valence electrons until their outer-most energy level is ‘full’
- Atoms that have 1,2 or 3 valence electrons will react chemically by losing them.
- Atoms that 5,6 or 7 valence electrons will react chemically by gaining more electrons until the outer-most energy level is ‘full’ (i.e. Octet rule)
- Those atoms that have 4 valence electrons will react chemically by losing them (metals) or gaining more (non-metals) until the outer-most energy level is ‘full’
Element Ca Metal or non-metal? #valene electrons? Lewis diagram? Electron loss/gain?
Metal
2
.Ca.
Will lose 2
What is an ion?
An atom that has lost or gained electrons and has become charged.
What is an cation?
Metals that lose electrons and become positively changed.
What is an anion?
Nonmetals that gain valence electrons and became negatively charged.
What are the steps for ionic bonding?
- Identify the metal and the non-metal and how many valence electrons each will gain or lose.
- Draw the Lewis diagram for one metal and one non-metal atom.
- Transfer as many valence electrons as possible (show with arrows)
4 add more metals or non metals atoms and continue transferring electrons until all metal atoms have lost all valence electrons and all nonmetals atoms have a full valence shell. - Record the ions formed and the formula of the product.
Do examples**
Write the formula for Li2O
Lithium Oxide
Write the formula for CaP2
Calcium floride
Write the formula for Ra3N2
Radium nitride
What are the steps to writing an ionic compound?
- Write the name of the metal (the first symbol in the compound)
- Write the name of the non-metal (the second symbol in the compound) changing the ending to “ide”
What are the steps for writing the formulas of ionic compounds?
- Write the symbol for each part of the compound first the metal then the non-metal.
- Write the change of the ion above each symbol.
- Cross the charge numbers over and write the formula
- If need be, reduce the formula
* do questions
What makes water?
2 hydrogen 1 oxygen
Make diagram*
Steps for writing names of molecular compounds.
- Look at the number after the first symbol in the compound and write the prefix for the number (not mono)
- Write the name of the first symbol.
- Look at the number after the second symbol in the compound and write the prefix for the number.
- Write the name of the second symbol and change the ending to “ide”
Writing the name for CCl4
Carbon tetra chloride
Write the name for N2O3
Diitrogen trioxide
Write the name for IBr2
Iodine dibromine
Steps for writing the formula for a molecular compound
- Write the symbol for the first name in the compound.
- Now write the number after the symbol that matches the prefix in the first name.
- Write the symbol for the second name in the compound - remember the ending will be “ide” so don’t get confused about which element it is.
- Now write the number after the symbol that matches the prefix in the first name.
Write the formula for carbon dioxide
CO2
Write the formula for disphosphorous pentoxide
P2O5
Write the formula for Dinitrogen monoxide
N2O
Describe the reactivity of metals as you move down a group and non-metals as you move up.
Metals reactivity group 1+2 increases down the group
Halogens reactivity decreases down ten group
Noble gases are unreactive due to full valence shell
What are the general properties of an metal?
Are on the left and middle side of the periodic table
Hard
Malleable
Conducts heat and electricity
All solids but hydrogen which is a liquid
Most are sliver/grey
What are the general properties of non-metals?
Are on the top right Most are gases Many solids which are brittle One liquid Poor conductor Many colours
What are the general properties for metalloids?
Between metals and non-metals
Has mix of properties
What is an ionic compound?
A pure substance made up of at least one metal and one non-metal.
What is a covalent bond?
A connection between the atoms of non-metals where a pair of electrons are shared
What is a molecular compound?
A pure substance formed with 2 or more non-metals combined chemically.
What is an molecule?
A combination of two or more atoms held together by a covalent bond.
What are two differences between ionic and molecular bonding?
- Ionic is between metal + nonmetals, molecular(covalent) is between 2 or more non-metals.
- Ionic compounds are formed by the transfer of electrons while molecular compounds are formed by the sharing of electrons.
What is the relationship between atoms, elements compounds and molecules?
Atoms are the smallest particle of an element that has the property of the element. Elements chemically combine to form a compound. A compound is made up of 2 or more elements. A molecule is the smallest part of a compound that has the properties of the compound. Atoms join together to form molecules.
List 4 rules when using the bender burner.
- Tie long hair back
- Secure or remove loose clothing
- Other ten the equipment needed, clear the workplace
- Chick the Bunsen burner and gas hose for defects or leaks
- Once lit never leave a Bunsen burner unattended
Describe the hydrogen test?
Put calcium into water and collect the gas. Then light a wooden splint with the Bunsen burner and insert it into the test tube. You should he the lit splint “pop”
Describe the oxygen test?
Pour hydrogen peroxide into a test tube containing manganese dioxide then put the stopper on it. Next light the wooden splint with the Bunsen burner and blow it out. Insert it into the test tube. The glowing splint should relight.
Describe the carbon dioxide test?
Pour vinegar into a test tube containing baking soda. After reaction pour the gas into the other test tube with limewater. Shake the test tube. The limewater should turn cloudy white.
Steps to light a Bunsen burner.
- Turn the needle valve (controls the amount of oxygen in the air inlet) clockwise until it is fully closed. Open the needle valve by turning it counterclockwise three turns.
- Turn the barrel (controls the amount of oxygen in the air inlet) clockwise until it is fully closed. Open the air inlet by turning the barrel counterclockwise three turns.
- Connect the Bunsen burner to the gas source using the rubber gas hose.
- Open the gas source and strike a flint lighter to ignite the gas.
What does heterogenous mean?
Different throughout
What does homogenous mean?
The same throughout.
What a solvent?
What does the dissolving in a solution
What is a solute?
What is dissolved in a solution.
What was Democritus theory?
All matter can get divided into smaller prices until single particle is reached.
Indivisible partly is called an atom.
What was John Dalton’s theory?
Agreed with Democritus theory about how one divisible atom can be reached.
Atoms of the same element have the same size and mass
Atoms of different elements have different properties
Atoms of different elements can be combined to make a new substance
What was J.J. Thomson theory?
Discover electrons
Negative electrons are evenly distributed through the atom
What was Rutherford’s theory?
Gold foil experiment
Divided proton
Most of the atom is empty space
The nucleus is surrounded by electrons
What is Chadwick’s theory ?
Atom is meth with a tiny dense nucleus
The nucleus contains protons and neutrons
Negatively charged electrons circle through the empty space around the nucleus
What is Bohr theory?
Electrons orbit around the nucleus in shells
Each shell can hold a maximum number of electrons.
