Mendeleev’s periodic table was in error because when the elements were arranged by mass it resulted in several elements being placed in groups of elements with differing properties.
Explain how Mendeleev’s periodic table was in error how was this error fixed?
Newland’s law of octaves stated that elements properties repeated every eighth element. While this was not completely correct it did lead to the idea of a periodic pattern in the properties of elements.
Explain the contribution of Newland’s law of octaves to the development of the modern periodic table?
Mendeleev is given more credit because he published his organizational scheme and went on to demonstrate its usefulness. Mendeleev predicted the existence of properties of undiscovered elements and left blanks in his periodic table for them.
German chemist Lothar Meyer and Russian chemist Dmitri Mendeleev both propose similar periodic tables in 1869. Why is Mendeleev generally given credit for the periodic table?
Mendeleev arrange the elements in order of increasing atomic mass in the columns with similar properties.
How was Mendeleev’s periodic table organized?
The statement that there is a periodic repetition of chemical and physical properties of elements when they arranged by increasing atomic number.
What is the periodic law?
Oxygen – nonmetal, barium- metal, germanium – metalloid, Iron – metal, neon – nonmetal, and praseodymium-metal
Identify each of the following as a metal nonmetal are metalloid. Oxygen. Barium. Geranium. Iron. Neon. Praseodymium.
Metals are elements that are generally shiny went smooth and clean solid at room temperature and good conductors of heat and electricity most metals also are malleable or ductile.
Describe the general characteristics of metal
Alkali – group 1a, halogens- Group 7a, alkaline earth metals -Group 2a, noble gases – Group 8A
What group are each of these items Alkali metals, halogens, alkaline earth metals, noble gases.
oxygen-representative, barium-representative, germanium-representative, iron-transition, neon-representative, and praseodymium-transition.
Identified these elements as representative elements or transition element oxygen, barium, germanium, iron, neon, and praseodymium.
left
A shiny solid element also is ductile. What side of the periodic table is it likely to be found?
Metalloids are elements with physical and chemical properties of both metals and nonmetals. Boron, geranium, and silicon
What are the general properties of a metalloid? List three metalloid element?
To separate the metals and nonmetals
What is the purpose of the heavy stairstep to line on the periodic table?
One type of numbering to use is groups are numbered one through eight followed by the letter a or B. Another more recent membrane system uses numbers one through 18 above each for group.
Describe the two types of numbering used to identify groups on the periodic table?
Bromine – Br, Mercury – Hg
Give the name and symbol for the two elements that are liquid at room temperature.
Radon-Rn
Give the name and symbol for the noble gas with the greatest atomic mass?
Uranium – U
Give the name and symbol of an inner transition metals.
They are in the same group
Why didn’t elements chlorine and Ioline have similar chemical properties?
The group number is the number valence electrons in the element.
How are the numbers of valence electrons of the group a elements related to the group number?
The energy level of an element Boelens electrons indicates the period on the periodic table in which it is found?
How is the energy level of an atoms valence electrons related to the period it is in on the periodic table?
Eight except for helium which has two
How many valence electrons do each of the noble gases have
S – block, P – block, D -block, F – block
What are the four blocks of the periodic table.
P⁶, which is the end of the configuration of most of the noble gases
In general, what electronic configuration has the greatest stability?
It is the group number, and the valence electrons energy level is what period the atom is on.
Explain how atoms valence electron configuration determines its place on the periodic table?
The radius of the atom is cannot be measured directly because it does not have a definite edge to the electrons cloud
Explain why the radius of an atom cannot be measured directly?
As you go down the groups the atomic number increases but the size of the atom increases. As you go right through the periods the atomic number goes up but the size of the atom decreases.
Given any two elements within a group, is the element with a larger atomic number likely to have a larger or smaller atomic radius than the other element?
Transition metals
Which elements are characterized as having their D orbitals filled with electrons as you move left to right across a period?
It is harder because Adams hold onto their inner core electrons much more strongly than they hold onto their valence electrons. A much larger ionization energy is needed for those inner core electrons.
Explain why it is harder to remove an inner shell electron then a valence electron from an atom?
right. groups one a through four a are positively charged ions with the larger positively charged ions on the left and gradually decreasing as you move right when you get to 5a you’re at the very large negative ions and then they gradually decrease as you move right.
An element forms a negative ion when ionized. On what side of the periodic table is the element located? Explain?
barium, magnesium, as you move down a group, an ion’s outershell are in higher principal energy levels, resulting in a gradual increase in ionic size.
Of the elements magnesium, calcium, barium, which forms the ion with the largest radius? The smallest radius? What periodic trend explains this?
The energy required to remove an electron from a gaseous atom.
What is iodization energy?
Each successive ionization of an electron requires a greater amount of energy because as you go inward the electrons closer to the nucleus have a larger pull on them
Explain why each successive ionization of an electron requires a greater amount of energy?
8
Which group has the highest ionization energies?
an atom with a charge
Define an ion?
The ionic radius of nonmetals increase compared to the atomic radius, because when an atom becomes a negative ion it gains an electron and the size of the radius increases.
How does that ionic radius of a nonmetal compare with its atomic radius? Explain why the changes and radius occur.
As you move across the periods from left to right the atomic radii decrease because none of the electrons come between the valence electrons and the nucleus the valence electrons are not shielded from the increased nuclear charge and the result is they are pulled towards the nucleus.
Explain why atomic radii decrease as you move left to right across a period.
The octet rule states that atoms tend to gain, lose, or share electrons in order to acquire a full set of eight valence electrons.
Explain the octet rule.
8, 3, 1
How many valence electrons do elements in the following groups have. Group 8A. Group 3A. Group 1A.
Na⁺, it has a smaller positive charge so its radius is
Na⁺ and Mg²⁺ ions each have 10 electrons surrounding their nuclei which ion would you expect to have the larger radius? why
The relative ability of an element’s atoms to attract electrons in a chemical bond
What is electronegativity?
Electronegativity decreases as you move down a group and increases as you move to the right.
How does electronegativity change within the periodic table?
