Chemistry Flashcards
What is chemistry?
The study of properties of matter
What does caustic mean?
Anything that will burn or destroy living tissue
What is the PMOM?
See image 20
How is matter classified?
see image 21
What are the different types of mixtures?
Mechanical mixtures can be easily separated, suspensions settle out, and colloids are where smaller particles are evenly distributed throughout another. \Solutions are where a solute is completely dissolved in a solvent. Emulsions are a type of colloid where a liquid is evenly distributed in another liquid, and has an emulsifying agent to prevent fat particles from joining together(see image 22). Milk is a colloid and dirty water is a suspension. Trail mix is a mechanical mixture and apple juice is a solution
What is the Tyndall effect?
Because colloids look so much like solutions, we need a test to see whether or not a substance is a colloid or solution. The Tyndall effect is where if you shine a light on a colloid, it will scatter while solutions do not due to the smaller particle size
What is the difference between physical and chemical changes?
Physical changes are changes in appearance or structure while chemical changes are changes in chemical composition
What are alchemists and who are some famous ones?
They are a chemist-pharmacist-mystic profession and Sir Francis Bacon theorized that science should be built on experimental evidence and Robert Boyle discovered that elements could form compounds
What is the Law of conservation of mass?
In a chemical change, the total mass of the new substances is the same as that of the old, developed by Antoine Lavoisier
What is the Law of Definite composition?
Compounds are always formed by a certain proportion of elements
What is electrolysis?
The process of separating compounds by running a current through them
What is Dalton’s Atomic Theory?
see image 23, and he thought that atoms were like round billiard balls
What is an element?
A pure substance made up of one type of atom
What is a compound?
2 or more Elements chemically joined together
How did the history of atomic models go?
See image 24
What is the difference between a law and a theory?
Laws describe what happens while theories describe why they happen. Theories can be revised depending on new discoveries
What are element symbols?
Symbols for the elements of the periodic table by the IUPAC
What are metals?
They are shiny elements that are quite ductile and malleable eg iron
What are nonmetals?
They are elements that are quite brittle and not malleable eg oxygen
What are metalloids?
Elements that have the characteristics of both metals and metalloids eg silicon
What is a chemical family?
A group of related elements that have similar properties, and is a column in the periodic table. Each chemical family shares a certain number of electrons found in its outer shell, and when moving to the right, electrons are added onto the outer shell.
What are alkali metals?
Elements that are extremely reactive because of their odd electron count(1) in their outer shell and thus tendency to form compounds. Their easiest way to stabilize is to lose an electron
What are alkali earth metals?
Anything that is insoluble in water and unchanged by heat, and is fairly reactive but not as reactive as alkalis
What are noble gases?
Any gas that is very stable and cannot react easily
What are pre-transition elements and post-transition elements?
Pre-transition is right of the staircase while post is left, and post is very brittle and melts easier than regular transition metals
What are transition metals?
Metals right of the alkali and alkali earth, a perfect rectangle
What is the difference between malleability and ductility?
Malleability (mallet) is the ability for something to form thin sheets when crushed while ductility is how well it bends and stretches
What is a halogen?
Elements that are extremely reactive because of their odd electron count(7) in their outer shell and thus tendency to form compounds. Their easiest way to stabilize is to gain an electron
What is atomic mass?
The average mass of an atom of each element measured in amub (1/12 mass of atom of Carbon-12)
Who created the periodic table and how?
Dmitri Mendeleev in the 1860s by sorting elements by atomic mass
What is the atomic number of an element?
The number of protons in that element’s nucleus, resulting in not too many changes from Mendeleev’s original table
What is mass number?
The total amount of protons and electrons in an atom
What is a period?
A row in the periodic table, and each shares the same energy level and number of outer electron shells.
What is a chemical formula?
The scientific way to write a compound by listing how many of each element there is
What is a molecule?
A group of atoms bonded together, with no molecules losing or gaining electrons
What are diatomic molecules?
Molecules made of 2 of the same element, such as hydrogen, oxygen and nitrogen
What is a binary compound?
A compound made of 2 different elements
In groups of what are electrons generally found in?
2
Properties of ionic and molecular compounds
See image 26
What is a precipitate?
Small solid particles suspended in a liquid
What is an ionic compound?
A compound in which some atoms lose or gain an electron. It is made of one non-metal and one metal, where the metals lose electrons and the non-metals gain electrons
What is an ion?
A particle or group of particles with a positive or negative charge. These conduct electricity and tend to bond easily with ions of the opposite charge
What are polyatomic ions?
Ions with more than 1 element
What are Multivalent metal ions?
Some metal elements can make more than 1 type of ion, such as copper and iron
What do the columns of the periodic table mean?
Similar properties
Why are ionic solutions conductive?
When it dissolves in water, it forms positive and negative ions, which allows them to carry charges easily from one place to another
How are ionic compounds named?
With the ratio of each element, and the metal first followed by the non-metal with -ide
How do you name molecular compounds?
First element and the second with -ide ratio. With prefixes for ratio. Order is very strange
What is a chemical reaction?
Where 2 or more substances reorganize atoms to create other substances
What are reactants and products?
Reactants are the things put in the chemical reaction while products are the outcomes of the chemical reaction
How do you write a chemical reaction?
An equation but an arrow instead of an equal sign
What are chemical bonds?
Bonds that cause atoms to behave as a whole
How are chemical bonds broken?
Energy is added to break them and a lot of energy is released
What are exothermic reactions?
Chemical reactions that give off heat
What are endothermic reactions?
Chemical reactions that absorb heat
What is the reaction rate?
How fast a chemical reaction occurs
What is a catalyst?
A substance that increases reaction rate without being changed or changing the reaction’s output, only speed
What is an enzyme?
A natural catalyst made by organisms
What are inhibitors?
Opposite of catalysts, slow down reactions
What is corrosion?
The oxidation of of metals or rocks in the presence of air and moisture
What is the scientific name for rust?
Iron oxide, created when iron oxidizes
How do you prevent corrosion?
Coat the surface with paint or zinc. Coating it with zinc is called galvanization
What is combustion?
A highly exothermic reaction such as gasoline burning, wood burning, etc.
How do you find the number of neutrons in an element?
Atomic mass - Atomic number
