The History of the Periodic Table
The Modern Periodic Table
Trends
The Elements
Reverse Category (Q+A)
100
He created the first periodic table, and predicted the existence and properties of new chemical elements. His periodic table was based on atomic weights instead of atomic number.
What were Dmitri Mendeleev's main contributions to chemistry?
100
A column of elements in the periodic table. There are 18 of these in the periodic table containing elements with similar properties.
What is a group in the periodic table?
100
One-half the distance between the nuclei of two atoms. Increases towards bottom-left corner of periodic table.
What is atomic radius?
100
Fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At).
What are the halogens?
100
What is the atomic number of an element with 22 protons?
22
200
He is known for his establishment of truly scientific basis of the Periodic Table of the Elements by sorting chemical elements in the order of their atomic numbers. He discovered a systematic relation between wavelength and atomic number. He also predicted a number of missing elements and their periodic numbers in the Periodic Table.
What were Henry Moseley's main contributions to chemistry?
200
A row of elements in the periodic table. Elements of the same row have the same number of electron shells.
What is a period in the periodic table?
200
A chemical property describing an atom's ability to attract and bind with electrons. It increases towards the top-right corner of the periodic table.
What is electronegativity?
200
Includes the transition metals, which are the 38 elements in groups 3 through 12 of the periodic table and are both ductile and malleable, and conduct electricity and heat. Iron, cobalt, and nickel are three important transition metals. Iron is used in machinery and automobiles, cobalt is used in magnets, and nickel is used in coinage. They are part of the _ block elements.
What are the D block elements?
200
What is the electron configuration of carbon?
1s^2 2s^2 2p^2 OR [He] 2s^2 2p^2
300
Widely credited as the “father of modern chemistry”, he formulated a theory of the chemical reactivity of oxygen and co-wrote the modern system for the nomenclature of chemical substances.
What were Antoine Lavoisier’s main contributions to chemistry?
300
Electrons that appear in the outermost shell of an atom. They can participate in the formation of a chemical bond. They determine the ordering of groups in the periodic table.
What are valence electrons?
300
The radius of an atom's ion. It increases towards the bottom-left corner of the periodic table.
What is ionic radius?
300
Includes the inner transition metals (lanthanides and actinides), which are found below the rest of the elements in the periodic table, but are really part of periods 6 and 7. Lanthanides such as cerium, neodymium, and samarium are used to make strong permanent magnets. Actinides such as uranium and plutonium have been used in nuclear weapons. They are part of the _ block elements.
What are the F block elements?
300
What law states that many of the physical and chemical properties of the elements tend to recur in a systematic manner with increasing atomic number?
The Periodic Law
400
He found that when he listed the elements in order of increasing atomic weight, they seemed to fall into seven families that contained elements with similar chemical properties. His table listed these families in horizontal rows. He was the first to recognize that the elements fall into a pattern in which their properties repeat at regular intervals when they are listed in order of increasing atomic weight. He was also the first to assign atomic numbers to the elements.
What were John Newlands’s main contributions to chemistry?
400
They are commonly designated by a combination of numerals and letters that represent specific properties of the electrons associated with the orbitals—for example, 1s, 2p, 3d, 4f. They are arranged in order as you read across the periodic table.
What are orbitals?
400
The energy required to remove an electron from a neutral atom in its gaseous phase. Conceptually, it is the opposite of electronegativity. Increases towards the top-right corner of the periodic table.
What is ionization energy?
400
Includes hydrogen, alkali metals, and alkaline earth metals. The hydrogen family consists solely of hydrogen in the first group of the periodic table above the alkali metals which are also in the first group of the periodic table. The alkaline earth metals can be found in the second group of the periodic table. Uses for some of these elements include: hydrogen in water; alkali metals such as sodium in salt; alkaline earth metals such as magnesium in car engine casings. They are part of the _ block elements.
What are the S block elements?
400
What is the process of gaining or losing electrons to fill the outermost energy level called?
Ionization
500
He developed a periodic classification of the chemical elements. He worked on recalculating a number of atomic weights and made use of the periodic table for predicting and studying related elements’ chemical properties.
What were Lothar Meyer’s main contributions to chemistry?
500
The representation of the arrangement of electrons that are distributed among the orbital shells and subshells.
What is electron configuration?
500
The ability of an atom to accept an electron. It is a quantitative measure that measures the energy change that occurs when an electron is added to a neutral gas atom. It increases towards the top-right corner of the periodic table.
What is electron affinity?
500
Includes the boron group, the carbon group, the nitrogen group, the oxygen group, the halogens, and the noble gases. They are located on the right side of the periodic table. Uses for some of these elements include: boron in sports equipment such as golf clubs; carbon in coal; nitrogen in refrigerants; oxygen in the air; fluorine in toothpaste; helium in balloons. They are part of the _ block elements.
What are the P block elements?
500
What is a positive ion called and what is a negative ion called?
A positive ion is called a cation. A negative ion is called an anion.
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