Chem CH5
What is the pattern or periodicity of atomic numbers?
8,8,18,18,32
Of the elements gallium, Ga, bromine, Br, and calcium, Ca, which has the highest electronegativity? Explain your answer in terms of periodic trends.
All of these elements are in the fourth period. Bromine has the highest atomic number and is farthest to the right in the period. Bromine should have the highest electronegativity because electronegativity increases across the periods.
Without looking at the periodic table, identify the group, period, and block in which the element that has the electron configuration [Xe]6s2 is located.
Block: s (nS^2) Period: 6 (Ns^2) Group: 2 (ns^2)
Describe Moseley's periodic table
-arranged according to atomic number
low ionization energy = ______ electrons easily
loose
describe the location of the "d" block
the 4x10 rectangle in between the s and p block
describe the location of the "p" block
the 6x6 square on the right side of the periodic table
Describe Mendeleev's periodic table
-in order of atomic mass -repeating patterns referred to as periodic -had several empty spaces (predicted the existence of elements that would fill these spaces)
What were the elements that Mendeleev predicted would be discovered
Ekaaluminium, Ekaboron, Ekasilicon
Consider two main-group elements, A and B. Element A has a first ionization energy of 419 kJ/mol. Element B has a first ionization energy of 1000 kJ/mol. Decide if each element is more likely to be in the s block or p block. Which element is more likely to form a positive ion?
Element A has a very low ionization energy, which means that atoms of A lose electrons easily. Element A is most likely to be an s-block metal because ionization energies increase across the periods. Element B has a very high ionization energy which means that atoms of B have difficulty losing electrons. Element B would most likely lie at the end of a period in the p block. Element A is more likely to form a positive ion because it has a much lower ionization energy than element B does.
Which element(s) is/are an exception to the group/column organization and why
Hydrogen - does not share the same properties as elements of Group 1 despite its location Helium - part of group 18 because it possesses special chemical stability
Without looking at the periodic table, write the electron configuration for the Group 1 element in the third period. Is this element likely to be more reactive or less reactive than the element described in (a)?
In a third-period element, the highest occupied energy level is the third main energy level, n = 3. The 1s, 2s, and 2p sublevels are completely filled. This element has the following configuration: 1s22s22p63s1 or [Ne]3s1 Because it is in Group 1, this element is likely to be more reactive than the element described in (a), which is in Group 2.
Give an example of a column or group on the periodic table
Noble gasses (last column), alkaline metals (first column)
Characterize the p block
On the right it contains all of the nonmetals except hydrogen and helium, as well as all six metalloids, on the left and on the bottom it includes eight metals
Of the elements magnesium, Mg, chlorine, Cl, sodium, Na, and phosphorus, P, which has the largest atomic radius? Explain your answer in terms of trends of the periodic table.
Sodium has the largest atomic radius All of the elements are in the third period. Of the four, sodium has the lowest atomic number and is the first element in the period. Atomic radii decrease across a period.
Name the block and group in which each of the following elements is located in the periodic table. Then, use the periodic table to name each element. Identify each element as a metal, nonmetal, or metalloid. Finally, describe whether each element has high reactivity or low reactivity. a. [Xe]4f145d96s1
The 4f sublevel is filled with 14 electrons. The 5d sublevel is partially filled with nine electrons. Therefore, this element is in the d block. The element is the transition metal platinum, Pt, which is in Group 10 and has a low reactivity.
Without looking at the periodic table, write the outer electron configuration for the Group 14 element in the second period. Then, name the element, and identify it as a metal, nonmetal, or metalloid.
The group number is higher than 12, so the element is in the p block. The total number of electrons in the highest occupied s and p sublevels is therefore equal to the group number minus 10 (14 − 10 = 4). Two electrons are in the s sublevel, so two electrons must also be present in the 2p sublevel. The outer electron configuration is 2s22p2. The element is carbon, C, which is a nonmetal.
Describe group 17, the "halogens"
The halogens are the most reactive nonmetals and react vigorously with most metals
Name the block and group in which each of the following elements is located in the periodic table. Then, use the periodic table to name each element. Identify each element as a metal, nonmetal, or metalloid. Finally, describe whether each element has high reactivity or low reactivity. [Xe]4f66s2
The incomplete 4f sublevel shows that the element is in the f block and is a lanthanide. Group numbers are not assigned to the f block. The element is samarium, Sm. All of the lanthanides are reactive metals.
Name the block and group in which each of the following elements is located in the periodic table. Then, use the periodic table to name each element. Identify each element as a metal, nonmetal, or metalloid. Finally, describe whether each element has high reactivity or low reactivity. b. [Ne]3s23p5
The incompletely filled p sublevel shows that this element is in the p block. A total of seven electrons are in the ns and np sublevels, so this element is in Group 17, the halogens. The element is chlorine, Cl, and is highly reactive.
An element has the electron configuration [Kr]4d55s1. Without looking at the periodic table, identify the period, block, and group in which this element is located. Then, consult the periodic table to identify this element and the others in its group.
The number of the highest occupied energy level is 5, so the element is in the fifth period. There are five electrons in the d sublevel, which means that it is incompletely filled. The d sublevel can hold 10 electrons. Therefore, the element is in the d block. For d-block elements, the number of electrons in the ns sublevel (1) plus the number of electrons in the (n − 1)d sublevel (5) equals the group number, 6.
What is unique about the d block elements?
They are metals with typical metallic properties and are often referred to as transition elements.
Name the block and group in which each of the following elements is located in the periodic table. Then, use the periodic table to name each element. Identify each element as a metal, nonmetal, or metalloid. Finally, describe whether each element has high reactivity or low reactivity. . [Ne]3s23p6
This element has a noble-gas configuration and thus is in Group 18 in the p block. The element is argon, Ar, which is an unreactive nonmetal and a noble gas.
What is an ion?
an Ion is an atom or group of bonded atoms that has a positive or negative charge, any process that results in the formation of an ion is ionization
Describe the modern periodic table
an arrangement of the elements in order of their atomic numbers so that elements with similar properties fall in the same column, or group
Where are the metalloids located on the periodic table?
between nonmetals and metals in the "p " block
among main group elements (block p and s ) ionization energies ________ as you go down the groups
decrease
cationic and anionic radii _____ across a period
decrease
electron affinity _______ down groups
decreases
high ionization energy = ______ electrons easily
do not loose
cationic and anionic radii ______ down a group
increase
ionization energies of the main group elements (block p and s) ______ across each period
increase
electronegativity ______ across periods and __________ down a group
increase, decrease
Electron affinity ________ across periods
increases
atoms tend to be __________ the farther down in a group they are found because of the _______ size of the electron cloud around an atom as the number of electron sublevels __________.
larger, increasing, increases
define anion
negative ion (gaining one or more electrons)
which blocks include the "main group elements"?
p and s
define cation
positive ion (loosing one or more electrons)
define atomic radii
radius of an atom, can vary under different conditions, may be defined as one-half the distance between the nuclei of identical atoms that are bonded together
What are the four "blocks" on the periodic table
s,p,d,f
atoms tend to be ________ the farther to the right they are found on the periodic table, which is caused by the increasing _______ charge of the nucleus, which attracts ______ towards the nucleus.
smaller, positive, electrons
What is the periodic law?
states that the physical and chemical properties of the elements are periodic functions of their atomic numbers
define electron affinity
the energy change that occurs when an electron is aquired by a neutral atom
Define ionization energy
the energy required to remove one electron from a neutral atom of an element
characterize the "f" block
the first row contain the lanthanides (shiny metals similar to group 2 alkaline metals) and the second row contains the actinides (all radioactive)
describe the location of the "s" block
the first two columns on the left side of the periodic table
what is electronegativity
the measure of the ability f an atom in a chemical compound to attract electrons from another atom in the compound
describe the location of the "f" block
the two rows of elements that usually appear below the rest of the table
the name for the electrons in the outermost energy level
valence electrons