Chapter 7 Chem 130

Why are the electron affinity values for the noble gases endothermic?

An electron added to a noble gas must go in the next higher energy level.

Alkaline earth metals reactivity

Beryllium does not react with water Magnesium only reacts with steam react readily with water increases as you go down a group

Where will the largest jump in ionization energies occur for aluminum?

Between the third and fourth ionization energies

Which element will release the most energy when gaining an electron? Chlorine Helium Sodium Carbon

Chlorine

Identify the largest ion. Cl- F- Na+ Li+

Cl-

Which element is the most metallic? Cs Mn Si O

Cs

Came to the same conclusion about how elements should be grouped

Dmitri Mendeleev and Lothar Meyer

The periodic trend for electron affinity values is not as consistent as for other trends. Which statement best describes the trend? -Electron affinity becomes more negative going from left to right but does not have a clear trend going from top to bottom for most columns. -Electron affinity becomes more negative going from top to bottom but does not have a clear trend going from left to right. -Electron affinity does not have a clear trend in either the rows or columns. -Electron affinity only has a trend in group 1A metals becoming more negative from top to bottom.

Electron affinity becomes more negative going from left to right but does not have a clear trend going from top to bottom for most columns.

discovered the nuclear atom

Ernest Rutherford

Which element has the least metallic character? F Si Na Cs

Flourine, F

Which element will react with these noble gases to form compounds? Fluorine Chlorine Sodium Sulfur

Fluorine

Group 7A

Halogens

Which element requires the most energy to lose one electron? Helium Fluorine Potassium Cesium

Helium

developed the concept of atomic number experimentally. The number of protons was considered the basis for the periodic property of elements

Henry Mosely

Which one of the following statements is true regarding ionization energies? -Ionization energies are all endothermic. -First ionization energies are exothermic, while second and successive ionization energies are endothermic. -Ionization energies are all exothermic. -Ionization energies for removing valence electrons are exothermic and endothermic for removing core electrons.

Ionization energies are all endothermic

Which element has the smallest ionization energy? K Ne Kr H

K

Which pair gives the more metallic element first? K, Li Ge, Ga B, Al Sn, Pb

K, Li

This person's table was based on atomic masses. It was the most fundamental property of elements known at the time.

Mendeleev's

Which sequence lists the ions in order of increasing radius (smallest to largest)? Mg2+ < Na+ < F− < O2− Na+ < Mg2+ < O2−< F− O2− < F− < Na+ < Mg2+ F− < O2− < Mg2+ < Na

Mg2+ < Na+ < F− < O2−

Which sequence lists the atoms in order of increasing atomic radius (smallest to largest)? O < C < Si < Al Li < Mg < Al < Ge B < C < N < O H < He < F < Ne

O < C < Si < A

Group 6A

O, S, Se are nonmetals Te is a metalloid Po is a metal

Group 6A

Oxygen Group

Which of the following elements has the largest atomic radius? Rb Xe Ne Li

Rb

Compare the outermost electron in each of the following atoms. Which one will experience the smallest effective nuclear charge? Sodium Potassium Calcium Beryllium

Sodium

Which one of the following has the smallest atomic radius? Sulfur Silicon Sodium Selenium

Sulfur

The outermost electron of boron experiences a lower effective nuclear charge than carbon. Why?

The nuclear charge increases from boron to carbon, but there is no additional shielding.

What factor causes the atomic radius to increase while moving down the periodic table, from top to bottom?

The number of electron shells increase.

effective nuclear charge formula

Z-S

Nonmetal oxides are...

acidic

Group 1A

alkali metals

soft metallic solids found only in compounds in nature metallic properties

alkali metals

Group 2A

alkaline earth metals

nonmetals form....

anions

Z

atomic number

Metal oxides tend to be...

basic

half the distance between nuclei in a bond

bonding atomic radius

metals form...

cations

hydrogen in acid compounds are...

covalent

Ionization energy __________ moving down the periodic table from top to bottom. In moving across the periodic table, from left to right, ionization energy __________.

decreases increases

ionic size ___________ with an ____________ nuclear charge

decreases increasing

Alkali metals show trends, such as electron affinity and melting point, that are not typically seen in other groups of metals. Moving from lithium to cesium, the melting point _____ and the electron affinity becomes _____.

decreases more positive

Atomic radius trend

decreases from left to right across a period increase from top to bottom of a group

What do I values depend on?

effective nuclear charge and average distance of the electron from the nucleus

the energy change accompanying the addition of an electron to a gaseous atom

electron affinity

what are flames caused by

electronic transitions

Why are anions larger than their parent atom?

electrons are added and repulsions between electrons are increased

alkali metal reactions with water are....

exothermic

electron affinity is typically...

exothermic (negative)

Smaller atoms have ___ ionization energies

higher

Properties of Alkali earth metals

higher densities and melting points than alkali metals ionization energies are low, but not as low as alkali metals

when hydrogen reacts with metals, what forms

hydride anions

Moving down the periodic table, from top to bottom, does the metallic character increase, decrease, or stay the same for the elements in the same column?

increases

Group 7A, the halogens, show periodic trends with respect to their melting point, boiling point, and density. As you move down the column, the melting and boiling points _____ and the density _____.

increases increases

For the outermost electron of an atom, effective nuclear charge _________________ as you go from left to right on the periodic table. This is because electron shielding _____________________, due to electrons being added to the same energy level as the outermost electron.

increases stays constant

First Ionization energy trend

increases across a period decreases down a group

Effective nuclear charge trend

increases across a period slightly increases down a group

what are the sizes of ions determined by?

interatomic distances in ionic compounds

compounds formed between metals and nonmetals are typically...

ionic

the minimum energy required to remove an electron from the ground state of a gaseous atom or ion

ionization energy

ions have the same number of electrons

isoelectric series

Noble gases

large ionization energies positive electron affinities relatively unreactive found as monoatomic gases

anions are ________ than their parental atoms

larger

Anions are _____ than their neutral parent atom, and cations are _____ than their neutral parent atom.

larger smaller

alkali metallic properties

low densities and melting points low ionization energies

electrical semiconductors

metalloid

substances containing only nonmetals are...

molecular compounds

Group 8A

noble gases

half of the shortest distance separating two nuclei during a collision of atoms

nonbonding atomic radius, or van der Waals

on the right side of the periodic table

nonmetal

Electron affinity trend

not much change in a group increases across a period 2A is full 5A is half full 8A is full

Electrons are attracted to the _____________ and repelled by ___________________________.

nucleus other electrons

lithium + oxygen

oxide

O2

oxygen gas (dioxygen)

Which pair lists the element with the lower first ionization energy first? Oxygen, fluorine Magnesium, calcium Chlorine, sulfur Helium, neon

oxygen, fluorine

O3

ozone gas

the repetitive pattern of a property for elements based on an atomic number

periodicity

sodium + oxygen

peroxide

S

screening constant

Properties of metals

shiny luster, conduct heat and electricity, malleable and ductile, solid at room temperature, low ionization energies/form cations easily

Cations are _______ than their parental atoms

smaller

properties of nonmetals

solid, liquid, or gas solids are dull, brittle, and poor conductors large negative electron affinity, so they form anions easily

K, Rb, Cs, + oxygen

superoxides

What does ionic size depend on?

the nuclear charge number of electrons orbitals in which electrons reside

Why are cations smaller than their parent atom?

the outermost electron is removed and repulsions between electrons are reduced

Halogens

typically nonmetals have highly negative electron affinities so they exist as anions in nature react with metals to form halides