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Flashcards in Chemistry Deck (37):


-when an atom is electrically charged
-also known as ionic state
-usually when in a solution or in the form of a chemical compound
-either lost electrons, positive charge or gained electrons, negative charge


periodic table

- rows called periods
-columns called groups
-table of known elements arranged according to their properties
-makes it possible to predict the charge of an atom


Group charges

-Group IA - +1
-Group IIA- +2
-Group IIIA- +3
-Group IV- +4 or -4
-Group VA -3
-Group VIA -2
-Group VIIA -1
-Group VIIIA- noble gas, no charge in solution, neutral


number of electrons in the outer shell

- Group IA has 1 electron in the outer shell
- Group IIA has 2 e-
- Group IIIA has 3 e-
-Group IVA has 4 e-


atomic number

- the number of protons in the nucleus
-it defines an atom as a particular element
-number of protons never changes
-located on the top of each element on the periodic table


atomic mass

- the average mass of each of that element's isotopes
- isotopes are different kinds of the same atom that vary in weight
-protons and neutrons have similar mass
- number at the bottom of the square on the periodic table
- number of protons remains same but the number of neutrons varies to make different isotopes



- mixtures of different elements to create a single matter
-elements in combination with one another


chemical equations

- like recipes
-ingredients, called reactants, react to produce desired end results or compounds, called products
-Reactants -----> Products
-arrow is also present, signifies direction of the reaction


the law of conservation of mass

-that mass cannot be created or destroyed during a chemical reaction
-equation must be balanced
-same number of each element must be represented on both sides of the equation



- a state in which reactants are forming products at the same rate that products are forming reactants
- can be reversible
-A+B C+D


4 ways to increase rate of reaction

1. increase the temperature in the reaction
2. increase the surface area of the reactants
3. add a catalyst
4. increase the concentrations of reactants


Increase rate of reaction: Temperature increase

- causes the particles to have a greater kinetic energy, causing them to move faster, increasing their chances of contact and the energy in which they collide
-contact is when the chemical reaction occurs


increase rate of reaction: increasing the surface area

- increasing surface area of particles in the reaction gives the particles more opportunity to come into contact with one another


increase rate of reaction: catalyst

-accelerates a reaction by reducing the activation energy or the amount of energy necessary for a reaction to occur
-catalyst is not used up in the reaction and can


increase rate of reaction: increasing concentration

-increasing concentration of the reactants will cause more chance collisions between the reactants and produce more products



- defined as a homogeneous mixture of two or more substances
-in the solution there is solute, the part or parts that are being dissolved and the solvent, the part that is doing the dissolving



-solid solutions of metals to make a new once such as bronze, which is copper and tin, or steel, which is iron and carbon, and may contain, tungsten, chromium and mangenese



a specific type of alloy in which a metal is dissolved in mercury



mixtures of matter that readily separate such as oil and water


molar concentrations

- a mole is 6.02 X 10^23 molecules of something
-known as Avogadro's number
-written as mol/L


chemical reactions

-making or changing chemical bonds between elements or compounds to create new chemical compounds with different chemical formulas and different chemical properties
-5 types of chemical reactions
-product is generally a molecule
-a molecule may have a subscript written after the chemical symbol O2


Synthesis Reaction: CR

- two elements combine to form a product
-2K+ + 2Cl- --> 2KCl


decomposition: CR

-opposite of synthesis because it breaks a compound into 2 components


combustion: CR

-self-sustaining, exothermic (creates heat) chemical reaction where oxygen and a fuel compound such as hydrocarbon react
- products are CO2 and H2O


single replacement: CR

- involve ionic compounds, whether or not the reaction will take place is based on the reactivity of the metals involved
-consist of a more active metal reacting with an ionic compound containing a less active metal to produce a new compound


double replacement: CR

- involve 2 ionic compounds
-the positive ion from one compound combines with the negative ion of another compound
-result is two new ionic compounds that have "switched partners"


Ionic bond

- an electrostatic attraction between two oppositely charged ions, or a cation and an anion
- bond is normally formed between a metal and a nonmetal


Covalent Bond

- when 2 atoms share an electron, in pairs
- strongest bond formed between two nonmetals
- if electrons are shared equally the bond is non-polar
- if electrons are not shared equally the bond is polar



- the difference in electronegativity values for the elements involved in the bond
-the greater the difference, the more polar the bond will be, or one side of the molecule will have a charge distinctly more positive and the other side of the moelcule will be more negative in charge


intermolecular forces

- not interactions between atoms within a molecule
-it is weaker forces of attraction between whole molecules
-hydrogen bonding, dipole-dipole interactions and dispersion forces


Hydrogen bond

- the attraction for a H atom by a highly electronegative element
-elements usually include F, O and N
- strongest of the intermolecular forces


Dipole-Dipole interactions

- the attraction of one dipole on one molecule for the dipole of another molecule
-a dipole is created when an electron pair is shared unequally in a covalent bond between two atoms or elements
-because they are shared unequally the molecule will have a positive and a negative end
-result is a weak bond between molecules, where the more highly electropositive end of a molecule is attracted to the electronegative end of another molecule
-weak intermolecular force


Dispersion Forces

- weakest of al intermolecular forces
-sometimes electrons within an element or compound will concentrate themselves on one side of an atom
-this causes temporary dipole, which would be attracted to another momentary dipole of opposite charge in another near element or compound



-are corrosive to metals
-they change blue litmus paper red and become less acidic when mixed with base
-compounds that are hydrogen or proton donors
-hydrogen in its ionic state is simply a proton
-hydronium is a water molecule plus a proton or a hydrogen
-all acids produce hydronium when placed in water (H3O+)
-H20 can act as an acid or base
-pH- lower than 7 is acidic



- also called alkaline compounds, are substances that denature proteins, making them feel very slick
-they change red litmus paper blue and become less basic when mixed with acids
-hydrogen or proton acceptors and hace hydroxide (OH)
-pH- higher than 7 is alkaline


Alpha radiation

- the emission of helium nuclei
-particles contain two protons and two neutrons causing them to have a charge of plus two
-the largest of the radioactive emissions, and penetration from alpha particles can generally be stopped by a piece of paper


beta radiation

- product of decomposition of a neutron or proton
-composed of high-energy, high-speed electrons that began as neutrons or protons
- either positive or negatively charged
-no mass so can be stopped by a thin piece of aluminum foil