Unit A: Section 2.0 Flashcards
What is the foundation for everything?
Elements
How many elements are in the periodic table?
118
What are elements?
Substances that cannot be broken down
How many naturally occurring elements are there?
90
How many synthetic elements are there?
25
What are the 3 groups that all elements can be classified into?
Metals
Non-metals
Metalloids
What category do most elements fall into?
Metals
Which category has the least elements?
Metalloids
What are the 6 common characteristics of metalloids?
- Silver or gray
- Shiny
- Good conductors
- Malleable
- Ductile
- Solid at room temperature
How does mercury differ from other metals?
It is a liquid at room temperature
What is room temperature?
25°
What is an example of a variable characteristic of a metal?
-How strongly metals react with other substances.
Which metals are highly reactive with air and water?
Sodium
What are some examples of inert metals?
Gold and platinum
What does inert mean?
Unreactive
How many elements are non-metals?
17
Why are non-metals grouped together?
Because of their lack of resemblance to metal instead of their similarities
What are about half of the non-metals grouped in?
A group called molecules
What type of variation is there in non-metals?
- Color
- State
What non-metal can etch glass?
Flourine
Which group on the periodic table is unreactive?
Noble gases
What are metalloids?
Elements that have properties that are intermediate between metals and non-metals
What properties does the periodic table organize elements by?
Chemical properties
Which side of the periodic table are the metals located on?
The left
Which side of the periodic table are the non-metals located?
The right
Where are the metalloids on the periodic table located?
In between the metals and non-metals
Why is hydrogen an exception?
It is a non-metal but behaves like metal in chemical reactions
How does an element get its symbol?
Its often an abbreviation derived from the elements name
What is a Period?
Each horizontal row
What is a Group or family?
Each vertical coulumn
What are Chemical families?
Groups of elements that have similar chemical and physical properties
What is the first group of the periodic table called?
Alkali metals
What are the characteristics of alkali metals?
- Soft
- Shiny
- Silver
What are alkali metals very reactive with?
Water
What do alkali metal compounds tend to look like?
White solids
What are chemical compounds?
A combination of 2 or more elements combined in a specific ratio
What is the second group of the periodic table?
Alkaline-earth metal
What are the physical characteristics of alkaline earth metals?
- Shiny
- Silver
- Kind of soft
- Not very soluble
What is the most non-reactive group of elements called?
Noble gases
Where are the noble gases located on the periodic table?
The very last group
What are some characteristics of noble gases?
- Non-reactive
- Not dense
- Non-flammable
Why are noble gases unable to combust?
They are not dense enough
What group is to the left of noble gases?
Halogens
What are the characteristics of noble gases?
- Poisonous
- Reactive with alkali metals
What are the 3 kinds of subatomic particles?
- Electrons
- Protons
- Neutrons
What are neutrons?
Neutral particles that add mass
What are electrons?
Negatively charged particles
What are protons?
Positively charged particles
Where are the protons and neutrons located?
The nucleus
What are energy levels of an atom?
A region of space near the nucleus that may be empty or contain electrons
How do you know the strength of electrons?
- Electrons further away from the nucleus have more energy
- Electrons closest to the nucleus have less energy
Why are electrons closest to the nucleus held tightly?
Because they are closest to protons
What is the organization of the levels of atoms?
2, 8, 8
How do elements bond with electrons?
Partly filled energy levels from 2 different atoms can overlap and electrons can exist in both of them at once
What does the atomic number tell you?
The number of protons an element has
What are isotopes?
Atoms of the same element that contain different numbers of neutrons
What is heavy hydrogen?
An isotope of hydrogen that contains 1 neutron
What does the mass number tell you?
The amount of protons and neutrons in an atom
How can the atomic symbol of an element be represented without being in the periodic table
- Mass number
- Element symbol
- Atomic number
What is the atomic molar mass?
The average mass of the isotopes of an element
What is ionization?
When elements gain or lose electrons
What is an ion?
An unbalanced or electrically charged electron
What does ionization create?
Metals and non-metals forming compounds
What are cations?
Positively charged atoms that form when atoms lose electrons represented by 1+
What are anions?
Negatively charged atoms that form when atoms gain electrons represented by -1
Why do atoms gain and lose electrons?
So they can become stable like noble gasses
What are valence electrons?
The electrons in the outer layer of an atom
What does valence mean?
The tendency to gain or lose electrons
What is the octet rule?
When atoms bond in such a way that they are able to have 8 electrons in their outer layer
Who is responsible for naming ionic compounds?
IUPAC the International Union of Pure and Applied Chemistry
How do ionic compound form?
When electrons transfer from one atom to another
What physically forms when 2 kinds of ions group together?
A crystal lattice
How do you name ionic compounds?
1) Name the cation
2) Name the anion and change the ending to ide
3) Balance the charges
What are multivalent ions?
Elements with more than 1 stable ion
How do you know what the charge is with multivalent electrons?
They use Roman numerals in the name
What are polyatomic ions?
Several non-metallic atoms joined together
What are the most common suffixes for polyatomic ions?
-ate and -ite
What is a molecule?
When 2 or more non-metallic atoms bond together
What state can molecular compounds exist in?
Solid, liquid, or gas
What are covalent bonds?
When atoms share electrons
What is a molecular element?
When atoms form molecules made up of only one atom such as N2
What does diatomic mean?
Only composed of 2 atoms
what are the number 1-10
mono di tri tetra penta hexa hepta octa nona deca
What are the properties of ionic compounds?
- High melting and boiling points
- Retention of Crystal Shape
- High solubility
- High conductivity
What is a precipitate?
A solid with a low solubility that forms solutions
What is an electrolyte?
Any solution that can conduct electricity
What are the properties of molecular compounds?
- Low melting and boiling points
- Weak
- Not conductive
What does polar mean?
Each molecule has a positive and negative end
What is an example of a product that is safe until thrown away?
Batteries that contain mercury
What are chlorofluorocarbons?
Non-toxic flammable chemicals used mainly in cooling systems
What is the problem with chlorofluorocarbons?
They are catalysts in the upper atmosphere and cause destruction of the earth’s ozone layer
What are the 2 most common recreational substances?
Alcohol and Nicotine
Why is alcohol considered to be a drug?
Because of its affects on the body
How does alcohol affect the body?
Destruction of liver, kidneys, and brain cells
What is physical dependance?
Aka addiction. When body becomes used to a drug and needs it to function
What is psychological dependence?
When the use of the drug is linked to certain moods or feelings and when the drug wears off the feeling disappears
What is nicotine?
A highly addictive chemical present in all tobacco products
What makes cigarettes dangerous?
-Large amounts of carbon dioxide
-Tar
-Formaldehyde
-Benzene
-
What body systems are damaged by smoking?
Respiratory and circulatory
What is an acid?
A compound that dissolves in water to form a Ph lower than 7
What is a base?
A compound that dissolves in water to form a Ph of greater than 7
What Ph is saliva?
It is highly basic so that your teeth won’t dissolve
What type of acid does the stomach make?
Hydrochloric acid strong enough to burn
What does the hydrochloric acid in your stomach do?
- Dissolves food
- Turns on an enzyme called pepsin
What does pepsin do in your stomach?
Speeds up digestion of protein into amino acids
What would happen if pepsin was not deactivated before reaching the intestines?
It would digest the digestive tract
What does the pancreas produce?
Sodium Hydrogen Carbonate
What does the sodium hydrogen carbonate do in the body?
It neutralizes the stomach acid and the pepsin
What does the sodium hydrogencarbonate do after neutralizing the stomach acid?
It goes into the bloodstream making it slightly basic
What is a buffer?
A substance that can keep the pH of a substance nearly constant despite the addition of a small amount of an acid or base
What do acidic solutions taste like?
Sour
What do basic solutions taste like?
Bitter
What do basic solutions feel like?
Slippery
What do acidic solutions feel like?
Not slipper that’s for sure
What is a way to detect whether a substance is an acid or base?
Using a piece of metal. Acids try to dissolve metal while bases don’t do anything
What are the properties of acids?
- Sour
- Not slippery
- Corrodes metal
- Red litmus
- Conductive
- < 7
What are the properties of bases?
- Bitter
- Slippery
- No reaction to metals
- Blue litmus
- Conductive
- > 7
What are acid-base indicators?
Chemicals that are used to tell if solutions are acidic or basic
What is litmus?
A paper that changes color depending on acidity
What do the colors of litmus paper represent?
Red = Acid Blue = Base
What is a universal indicator?
A mixture of several indicators that change color at a specific acidity
What is the acidity of stomach acid?
1.5
What is the acidity vinegar?`
3
Every increase of what on the pH scale means what?
An increase of 10
How can you identify an acid in a chemical formula containing hydrogen?
- If the H appears on the left
- If COOH appears on the right
Why do most acids have aqueous at the end?
Because IUPAC reccomends it
What is a popular naming system for acids containing hydrogen?
If it has one metal they start it with hydro- and it with -ic
eg. Hydro-chlor-ic
How can you recognize a basic solution from its chemical formula?
- An OH combined with a metal is usually Basic
- And high solubility
What is neutralization?
When acids and bases mix together and they lose all their acidic and basic compounds
