Chapter 4 (Unit 9): Elements and the Periodic Table
metal
any of several chemical elements that are usually shiny solids that conduct heat or electricity and can be formed into sheets etc.
nonmetal
element that usually is a gas or brittle solid at room temperature, is not malleable or ductile, is a poor conductor of heat and electricity, and typically is not shiny; are reactive with other elements
Average atomic mass
equal to the number of protons plus the number of neutrons.
gamma radiation
high-energy radiation with no mass or charge; Gamma radiation- is used to directly increase the temperature of water in a nuclear reactor
States of Matter
is one of the distinct forms that matter takes on. Four states of matter are observable in everyday life: solid, liquid, gas, and plasma; Going from a solid to a liquid to a gas...the average kinetic energy of the molecules increases.
electrons
negatively charged particles
halogen
one of the elements of Group 17 of the periodic table (fluorine, chlorine, bromine, iodine, and astatine); halogens combine with most metals to form salts
noble gas
one of the elements of Group 18 of the periodic table (helium, neon, argon, krypton, xenon, and radon); noble gases are unreactive (also known as inert)
alkali metal
one of the elements of group 1 of the periodic table (lithium, sodium, potassium, rubidium, cesium, and francium); they react with other elements by losing one electron
alkaline earth metal
one of the elements of group 2 of the periodic table (beryllium, magnesium, calcium, strontium, barium, and radium); alkaline earth metals react by losing 2 electrons
What does the atomic mass and atomic number tell us about an element's radioactivity?
An atomic number greater than 83 and a large number of neutrons indicates radioactivity in an element.
metalloid
An element that has some characteristics of metals and some characteristics of nonmetals; all are solids at room temperature and are brittle, hard and somewhat reactive
Boyle's Law
Boyles Law- at constant temperature an INCREASE in pressure leads to a DECREASE in volume and vice versa (INDIRECT). One of the Gas Laws. When the pressure of a gas increases the volume decreases; A graph would show that the pressure of a gas varies inversely with its volume under constant temperature
Nonmetals
Elements to the right of the stair step plus hydrogen; are generally missing only a few electrons to complete their outer shell
Organize the types of radiation particles from fastest to slowest.
Gamma, Beta, Alpha...think GBA!
Explain the concept of half-life.
Half-life is the amount of time it takes for half of the Half-life is the amount of time it takes for half of the nuclei in a sample of radioactive atoms to undergo nuclear decay.
How was radioactivity discovered?
In 1896, the French scientist Henri Becquerel discovered the effects of radioactive decay quite by accident while studying a mineral containing uranium. Radioactivity is the name that Marie Curie gave to the spontaneous emission of radiation by an unstable atomic nucleus.
Atomic number
Indicates the total number of protons in the nucleus of an atom of an element. The atomic number also tells you the number of electrons in orbit around the nucleus of a neutral atom of an element.
Explain how nuclear fusion works.
Small nuclei combine to form larger nuclei and releases energy; Nuclear fusion creates new elements inside stars (and sun) when small nuclei combine to form larger nuclei.
Define Atom
Smallest unit of an element that has all the properties of that element
How are Periods and Groups/families organized on the periodic table?
The columns (organized vertically) on the period table are known as groups or families. The rows across the period table are know as the Periods. (REMEMBER..."PERIODS ACROSS, FAMILIES UP AND DOWN") .
valence electrons
The electrons in the outermost shell (main energy level) of an atom; these are the electrons involved in forming bonds.
List the elements in the Halogen Family
The elements are F-fluorine, Cl-Chlorine, Br-Bromine, I-Iodine, At-Astatine. All of the elements in group 17 are halogens. They have low boiling points and low melting points.
protons
positively charged particles in the nucleus of an atom
beta particle
a fast moving electron given off by a nucleus during radioactive decay
plasma
a fourth state of matter distinct from solid or liquid or gas and present in stars and fusion reactors
period
a horizontal row of elements in the periodic table
particle accelerator
a machine that moves atomic nuclei at higher and higher speeds until they crash into one another, sometimes forming heavier elements
diatomic molecule
a molecule that consists of two atoms of the same element
neutron
a small particle in the nucleus of the atom with NO electrical charge (neutral, zero, no charge)
corrosion
a state of deterioration in metals caused by oxidation or chemical action
semiconductor
a substance that can conduct electricity under some conditions but not under other conditions; used to make computer chips, transistors, and lasers
ductile
a term used to describe a material that can be pulled out into a long wire
group
a vertical column of elements in the periodic table; elements in a group share chemical properties
chemical symbol
abbreviation for the name of an element
conductivity
the ability of a material to allow either heat or electricity to flow through it
radioactive decay
the atomic nuclei of unstable isotopes releasing fast moving particles and energy; decay-atomic nuclei of unstable isotopes give off nuclear radiation
atomic mass
the average mass of all the isotopes of an element
nucleus
the center part of an atom
nuclear fusion
the combination of the nuclei of small atoms to form a larger nucleus; releases energy; The sun and stars are examples and are made up mostly of hydrogen.
reactivity
the ease and speed with which an element combines, or reacts, with other elements and compounds
atom
the smallest particle of an element
energy level
the specific amount of energy an electron has
mass number
the sum of the number of neutrons and protons in an atomic nucleus
atomic number
unique number of protons in the nucleus of an atom; it identifies an element
What types of particles and energy can radioactive decay produce?
Natural radioactive decay can produce alpha particles, beta particles, and gamma rays. Gamma rays are the most penetrating type of radiation, followed by beta and then alpha.
Define Gas
No definite volume or shape (particles spread out or expand and fill all the space available to them)
Hygrogen is in group 1 on the periodic table. Is Hydrogen an alkali metal?
No. All of the elements in group 1 of the periodic table (except hydrogen) are alkali metals. Hydrogen is part of the nonmetals. These nonmetals are the elements to the right of the stair step plus hydrogen.
Which elements are very un-reactive, meaning they do not often form compounds? Why?
Noble gases (column 18) do not react or combine with any element.
Explain how nuclear fission works.
Nuclear fission occurs when the nucleus of a large atom splits and two smaller atoms are formed and energy is released in the process
Define Valence electrons
Outer shell electrons (see your periodic tables to review valence numbers for each group/family)
Phase Changes
PHASE CHANGES- o Condensation-gas to a liquid o Sublimation-solid to a gas w/out the liquid state o Evaporation-liquid to a gas (vaporization at the surface)
Physical Change
Physical change-When a physical change occurs, it means that the substance changes its appearance but not its molecular identity or structure. Some examples of physical changes include: • shredding a piece of paper • drawing a metal such as copper into a wire • pounding a metal such as aluminum into thin sheets • breaking a sheet of glass.
Define Plasma
Plasma-a substance which contains ions and free electrons rather than neutral atoms; the ions and electrons are spread very far apart and are thus able to move independently of one another; plasmas possess the greatest amount of energy
Which particles in an atom have a positive charge? A negative charge? No charge?
Protons - positive charge Electrons - negative charge Neutrons- "neutral charge", "no charge", "zero charge"
Where are protons, neutron and electrons found?
Protons and neutrons are found in the nucleus. Electrons are located in the electron cloud; arranged in energy levels
tracer
Radioactive isotopes that are used to detect some medical issues; A radioactive isotope that can be followed through the steps of a chemical reaction or industrial process.
transition metal
An Element in group 3 through 12 of the periodic table; include most of the familar metals: copper, nickel, silver and gold
Chemical Change
A chemical change occurs when a substance changes its identity. For example, when copper metal is placed in a nitric acid solution, it reacts with the acid. The copper metal changes its molecular identity when it combines with the nitric acid, and it becomes copper nitrate. Chemical changes occur because chemical reactions have taken place. Some examples of chemical changes include: • silver metal reacting with sulfur to form sulfur oxide • burning hydrogen gas in air • heating a compound until it breaks down or decomposes
What are the properties of nonmetals?
A non-metal is an element that lacks most of the properties of a metal. Most nonmetals are poor conductors of electricity and heat and are reactive with other elements. Solid nonmetals are dull and brittle.
Describe Periods and how its used in the Periodic Table
A period is defined as an interval required for a cycle to repeat itself. In the periodic table, the periods extend from left to right and consist of as few as two elements to as many as thirty-two elements. Elements within the same period have the same number of energy levels. For example, since hydrogen and helium are in period 1, they only have electrons in the 1st energy level. Since potassium, calcium, and bromine are in the 4th period, however, they may contain electrons in as many as 4 energy levels.
Define Compounds
A pure substance made of two or more elements chemically combined in a set ratio. (ex. Water - H2O - 2 atom of Hydrogen and 1 atom of oxygen) Compound-2 or more elements chemically combined ex. Carbon dioxide- CO2 (1 atom of carbon and 2 atoms of oxygen)
What type of material can provide adequate protection from alpha radiation?
A sheet of paper will provide protection from alpha radiation.
periodic table
A table that shows the elements, their atomic number, symbol, and average atomic mass; elements with similar chemical properties are grouped together.
alpha particle
A type of nuclear radiation consisting of two protons and two neutrons; positively charge particles consisting of 2 protons and 2 neutrons given off by radioactive materials; A piece of paper will provide protection from alpha radiation.
malleable
Able to be hammered or pressed permanently out of shape without breaking or cracking
Where are the most reactive metals found on the periodic table?
Alkali metals are your most reactive metals. All of the elements in group 1 of the periodic table (except hydrogen) are alkali metals. They are soft metallic solids and have low melting points. They all have only one electron in their outer shell, which makes them highly reactive!
What are Alkali metals?
All of the elements in group 1 of the periodic table (except hydrogen) are alkali metals. They are soft metallic solids and have low melting points. They all have only one electron in their outer shell, which makes them highly reactive!
Halogens
All of the elements in group 17 are halogens. They have low boiling points and low melting points.
What are Alkaline earth metals?
All of the elements in group 2 of the periodic table are alkaline earth metals. They are hard metallic solids and have higher melting points than alkali metals. They all have two electrons in their outer shell. Though they are also highly reactive, they are less reactive than alkali metals.
What does the Atomic Number tell us about the number of electrons and protons in an element?
Atomic Number = Number of Protons = Number of Electrons Atomic number indicates the total number of protons in the nucleus of an atom of an element. The atomic number also tells you the number of electrons in orbit around the nucleus of a neutral atom of an element.
How did the atomic theory develop and change?
Atomic theory grew as a series of models that developed from experimental evidence. As more evidence was collected, the theory and models were revised.
Define isotope.
Atoms of the same element (atomic number does not change) that have different numbers of neutrons. (ex. Carbon 14 is an isotope of the element carbon. It has 8 neutrons- 2 extra)
isotopes
Atoms with the same number of protons that have different numbers of neutrons (ex. The atomic number of Carbon is 6. Its atomic weight is 12. Therefore, the element carbon has 6 Neutrons (12 - 6 = 6). Carbon 14 is an isotope of the element carbon. It has 8 neutrons- 2 extra). Therefore, its atomic weight is 6+8=14. The number of electrons or protons doesn't change. The atomic number is still 6)
Density Equation
BE ABLE TO SOLVE FOR DENSITY- density= m/v (REMEMBER YOUR UNITS!)
List the Alkaline Earth Metals
Beryllium, magnesium, calcium, strontium, barium, and radium. All of the elements in group 2 of the periodic table are alkaline earth metals. They are hard metallic solids and have higher melting points than alkali metals. They all have two electrons in their outer shell. Though they are also highly reactive, they are less reactive than alkali metals. The elements are Be, Mg, Ca, Sr, Ba, Ra.
Define metalloids.
Elements that share characteristics of both metals and nonmetals Elements along the stair step - B, Si, Ge, As, Sb, Te, Po, At; elements that share properties between typical metals and nonmetals.
Define Solution
Definite shape and definite volume (movement-vibration) particles packed tight together and in fixed positions; arranged in either a crystalline or amorphous form
Define Liquid
Definite volume but no definite shape (movement-particles free to move but remain in close contact)
Define Ductile.
Ductility describes a materials ability to be pulled out, or drawn, into a long wire (copper wire used in electrical wires and cables).
What are valence electrons?
Electrons in the outermost energy level of an atom
Groups/families
Elements are also organized vertically into columns. The columns are known as groups or families. Groups/families have the same valence electrons
What do the elements in the same column or family of the periodic table have in common?
Elements in same family or column have similar chemical properties.
Transition metals
Elements located in groups 3-12 on the periodic table are known as transition metals. These elements tend to be hard metallic solids, have high heat and electrical conductivities
How are elements that follow uranium?
Elements that follow uranium are made-or synthesized-when nuclear particles are forced to crash into one another.
How do you know the number of protons in an atom?
Look at the element's Atomic Number Atomic number indicates the total number of protons in the nucleus of an atom of an element. The atomic number also tells you the number of electrons in orbit around the nucleus of a neutral atom of an element.
Malleability
Malleability describes a materials ability to be hammered or rolled into flat sheets or other shapes - (ie, coins that are copper, nickel, silver are gold)
How are the metalloids useful?
Metalloids have some characteristics of both metals and nonmetals. The most useful properties of metalloids is their varying ability to conduct electricity.
What are some typical properties of metals?
Metals are-ductile (look at your vocabulary), malleable (vocabulary term), solid at room temperature (except Mecury) and good conductors of heat and electricity. Metals-elements to the left of the stair step; usually have 1, 2 or 3 electrons in their outer shell
Explain the characteristics of nonmetals.
Most are gases at room temperature. Elements to the right of the stair step plus hydrogen; are generally missing only a few electrons to complete their outer shell
Specific Heat Equation
SPECIFIC HEAT- BE ABLE TO SOLVE FOR HEAT LOST OR HEAT GAINED- o Q= (MASS) X (CHANGE IN TEMP) X (SPECIFIC HEAT) units will be in joules or kilojoules
Define radioactivity.
Spontaneous emission of radiation by an unstable atomic nucleus. Gives off high energy particles.
What is the modern model of the atom?
The modern model describes an atom as consisting of a nucleus that contains protons and neutrons, surrounded by a cloudlike region of moving electrons.
How is the modern periodic table arranged?
The modern periodic table is organized / arranged / ordered by each elements atomic number (or number of protons).
Define Half-Life.
The name for the time required to change a part of a radioactive element to a stable element.
What information about elements does the periodic table provide?
The periodic table tells you the atomic number (which tells you the number of protons and electrons). It also includes the mass number, which is the sum of the protons and neutrons in the nucleus of an atom. You can calculate neutrons by taking the atomic mass and subtracting the atomic number.
What are the physical properties of metals?
The physical properties of metals include shininess, malleability, ductility, and conductivity.
How does the reactivity of metals change across the periodic table?
The reactivity of metals tends to decrease as you move from left to right across the periodic table.
Where can you find familiar metals such as gold, silver, copper, and nickel? (What group?)
Transition metals - Elements located in groups 3-12 on the periodic table are known as transition metals. These elements tend to be hard metallic solids, have high heat and electrical conductivities
In what ways are radioactive isotopes useful?
Uses of radioactive isotopes include tracing the steps of chemical reactions and industrial processes, and diagnosing and treating disease.