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