Chemistry Flashcards
1
Q
ion
A
- 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
2
Q
periodic table
A
- 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
3
Q
Group charges
A
- 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
4
Q
number of electrons in the outer shell
A
- Group IA has 1 electron in the outer shell
- Group IIA has 2 e-
- Group IIIA has 3 e-
- Group IVA has 4 e-
5
Q
atomic number
A
- 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
6
Q
atomic mass
A
- 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
7
Q
compound
A
- mixtures of different elements to create a single matter
- elements in combination with one another
- NaCl
8
Q
chemical equations
A
- 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
9
Q
the law of conservation of mass
A
- 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
10
Q
equilibrium
A
- a state in which reactants are forming products at the same rate that products are forming reactants
- can be reversible
- A+B C+D
11
Q
4 ways to increase rate of reaction
A
- increase the temperature in the reaction
- increase the surface area of the reactants
- add a catalyst
- increase the concentrations of reactants
12
Q
Increase rate of reaction: Temperature increase
A
- 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
13
Q
increase rate of reaction: increasing the surface area
A
- increasing surface area of particles in the reaction gives the particles more opportunity to come into contact with one another
14
Q
increase rate of reaction: catalyst
A
- 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
15
Q
increase rate of reaction: increasing concentration
A
-increasing concentration of the reactants will cause more chance collisions between the reactants and produce more products
16
Q
solutions
A
- 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
17
Q
Alloys
A
-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
18
Q
amalgams
A
a specific type of alloy in which a metal is dissolved in mercury
19
Q
emulsions
A
mixtures of matter that readily separate such as oil and water
20
Q
molar concentrations
A
- a mole is 6.02 X 10^23 molecules of something
- known as Avogadro’s number
- written as mol/L
21
Q
chemical reactions
A
- 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
22
Q
Synthesis Reaction: CR
A
- two elements combine to form a product
- 2K+ + 2Cl- –> 2KCl
23
Q
decomposition: CR
A
-opposite of synthesis because it breaks a compound into 2 components
24
Q
combustion: CR
A
- self-sustaining, exothermic (creates heat) chemical reaction where oxygen and a fuel compound such as hydrocarbon react
- products are CO2 and H2O
25
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
26
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"
27
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
28
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
29
Polarity
- 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
30
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
31
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
32
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
33
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
34
acids
- 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
35
bases
- 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
36
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
37
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
