Chem Chapter 5 11/9/17

Anion

A negative ion is known as a what?

Cation

A positive ion is known as a what?

Alkalis

Alkali metals react strongly with water to produce hydrogen gas and aqueous solutions of substances known as whats?

Metalloids

All six of the whats (boron, silicon, germanium, arsenic,antimony, and tellurium) are also in the p block?

Atomic number

Also, as what increases going down a group, more electrons lie between the nucleus and the electrons in the highest occupied energy levels? This partially shields the outer electrons from the effect of the nuclear charge.

Reactive

Although they are less reactive than the alkali metals, the alkaline-earth metals are also too what to be found in nature as free elements?

Halogens (Group 17)

Among the elements of each period, the whats gain electrons most readily?

Decrease

Among the main-group elements, ionization energies generally decrease/increase down the groups.

Decrease

Anionic radii (increase/decrease) across each period for the elements in Groups 15-18. The reasons for this trend are the same as the reasons that cationic radii decrease from left to right across a period.

Ionization

Any process that results in the formation of an ion is referred to as what?

Increase

As a general rule, electrons (in relation to electron affinity) add with greater difficulty down a group. This pattern is a result of two competing factors. The first is a slight (decrease/increase) in effective nuclear charge down a group, which increases electron affinities

Increase

As a general rule, electrons (in relation to electron affinity) add with greater difficulty down a group. This pattern is a result of two competing factors. The second is an (increase/decrease) in atomic radius down a group, which decreases electron affinities.

Difficulty

As a general rule, electrons add with greater ease/difficulty down a group

Increase

As they are in atoms, the outer electrons in both cations and anions are in higher energy levels as one reads down a group. Therefore, just as there is a gradual (decrease/increase) of atomic radii down a group, there is also a gradual (decrease/increase) of ionic radii.

Hydrogen and helium

At its right-hand end, the p block includes all of the nonmetals except these two elements.

Kerosene

Because of their extreme reactivity with air or moisture, alkali metals are usually stored in what?

Decrease

Cationic radii (increase/decrease) across a period because the electron cloud shrinks due to the increasing nuclear charge acting on the electrons in the same main energy level

Increase

Electronegativities tend to (decrease/increase) across each period, although there are exceptions

Decrease

Electronegativities tend to either (increase/decrease) down a group or remain about the same

Easier

Electrons removed from atoms of each succeeding element in a group are in higher energy levels, farther from the nucleus. Therefore, they are easier/harder to remove?

Positive

For an isolated ion in the gas phase, it is always more difficult to add a second electron to an already negatively charged ion. Therefore, second electron affinities are all what?

10

For atoms of p-block elements, the total number of electrons in the highest occupied level is equal to the group number minus what?

Chemical properties

Generally the electron configuration of an atom's highest occupied energy level governs the atom's what?

Salts

Halogens react vigorously with most metals to form examples of the type of compound known as whats?

He arranged them according to various properties and looked for trends or patterns

How did Mendeleev arrange the cards he had with the elements' names on them? What did he look for?

It organizes the elements like musical notes

How does Newland's Law of Octaves work?

Alkali

However, because they are so reactive, this type of metal is not found in nature as free elements. They combine vigorously with most nonmetals.

John William Strutt and William Ramsay

In 1894, English physicist who (Lord Rayleigh) and Scottish chemist Sir who discovered argon, Ar, a gas in the atmosphere that had previously escaped notice because of its total lack of chemical reactivity. Back in 1868, another noble gas, helium, He, had been discovered as a component of the sun, based on the emission spectrum of sunlight. In 1895, the Scottish chemist showed that helium also exists on Earth

Henry Moseley

In 1911, the English scientist ______ _______, who was working with Ernest Rutherford, examined the spectra of 38 different metals. When analyzing his data, this man discovered a previously unrecognized pattern

Increase

In general, ionization energies of the main-group elements increase/decrease across each period.

Increase

In general, the atomic radii of the main-group elements increase/decrease down a group.

Krypton, Kr, and xenon, Xe

In order to fit argon and helium into the periodic table, Ramsay proposed a new group. He placed this group between the groups now known as Group 17 (the fluorine family) and Group 1 (the lithium family). In 1898, Ramsay discovered two more noble gases to place in his new group, what were they?

Cut with a knife

In their pure state, all of the alkali metals have a silvery appearance and are soft enough to be what?

Nuclear charge

Increasing what is responsible for both increasing ionization energy and decreasing radii across the periods?

No

Is aluminum a metalloid?

A periodic table of the elements

Mendeleev created a table in which elements with similar properties were grouped together— called what? This was published in 1869

Increasing atomic mass

Mendeleev noticed that when the elements on the cards were arranged in what order, certain similarities in their chemical properties appeared at regular intervals

It's observed physical and chemical properties

Mendeleev organized the elements like info on a research paper. He placed the name of each known element on a card, together with the atomic mass of the element and a list of what?

Scandium, Sc, gallium, Ga, and germanium, Ge.

Mendeleev's procedure left several empty spaces in his periodic table. In 1871, he boldly predicted the existence and properties of the elements that would fill three of the spaces. By 1886, all three elements had been discovered. What elements were they?

Atomic number

Moseley's work led to both the modern definition of atomic number and the recognition that this, not atomic mass, is the basis for the organization of the periodic table.

2+

Most d-block elements commonly form what type of ions in compounds. Some, such as iron and chromium, also commonly form 3+ ions

Most

Nitrogen, oxygen, and the halogens are the (least/most) electronegative elements

The size effect (increase in atomic radius)

Of the two reasons why electrons add with greater difficulty down a group, which predominates?

Lower

Proceeding down the column, the elements of Group 1 melt at successively (Higher/lower) temperatures.

Periodic

Such a repeating pattern as the one shown in Mendeleev's element cards (which occured at regular intervals) is referred to as what?

More

The Group 1 metals are (more/less) reactive than those of Group 2

Electron configurations

The Group 18 elements of the periodic table (the noble gases) undergo few chemical reactions. This stability results from the gases' special what?

Highest

The Group 18 elements, the noble gases, have the lowest/highest ionization energies. They do not lose electrons easily.

Alkali metals

The Group 2 metals are harder, denser, and stronger than the whats?

3+

The Group 3 elements form only ions with what charge?

Radioactive

The actinides are all what? The first four actinides (thorium, Th, through neptunium, Np) have been found naturally on Earth. The remaining actinides are known only as laboratory-made elements.

Least

The alkali and alkaline-earth metals are the (most/least) electronegative elements.

Decrease

The atomic radii of the d-block elements generally do what across the periods? However, this is less than that for the main-group elements because the electrons added to the (n − 1)d sublevel shield the outer electrons from the nucleus

Transition elements

The d-block elements are metals with typical metallic properties and are often referred to as whats?

Reactivities

The ease with which halogen atoms gain electrons is a major reason for the high whats of the Group 17 elements?

Reactive

The ease with which the single electron is lost helps to make the Group 1 metals extremely what?

Valence electrons

The electrons available to be lost, gained, or shared in the formation of chemical compounds are referred to as whats?

Alkali metals

The elements of Group 1 of the periodic table (lithium, sodium, potassium, rubidium, cesium, and francium) are known as the whats?

Halogens

The elements of Group 17 (fluorine, chlorine, bromine, iodine, and astatine) are known as the whats? These are the most reactive nonmetals.

Alkaline-earth metals

The elements of Group 2 of the periodic table (beryllium, magnesium, calcium, strontium, barium, and radium) are called the whats?

Metals

The elements of the s block are chemically reactive whats?

Second, third

The energies for removal of additional electrons from an atom are referred to as the _____ ionization energy (IE2), ______ ionization energy (IE3), and so on

Electron affinity

The energy change that occurs when an electron is acquired by a neutral atom is called the atom's what?

Ionization energy, IE

The energy required to remove one electron from a neutral atom of an element is the what?

Friedrich Ernst Dorn

The final noble gas, radon, Rn, was discovered in 1900 by the German scientist who?

Ions

The first ionization energies show that removing a single electron from an atom of a Group 18 element is more difficult than removing an electron from atoms of other elements in the same period. This special stability of the noble-gas configuration also applies to whats that have noble-gas configurations?

Atomic radius

The formation of a cation by the loss of one or more electrons always leads to a decrease in what because the removal of the highest-energy-level electrons results in a smaller electron cloud?

Atomic radius

The formation of an anion by the addition of one or more electrons always leads to an increase in what? This is because the total positive charge of the nucleus remains unchanged when an electron is added to an atom or an ion.

Octets

The highest occupied levels of the other noble gases contain stable whats? (Number)

Nuclear charge

The increase of ionization energy across each period is caused by an increasing what?

Group 2 alkaline-earth metals

The lanthanides are shiny metals similar in reactivity to the what type of metal? (List the group number too)

Sublevels

The length of each period is determined by the number of electrons that can occupy the whats being filled in that period?

Nonconductors

The metalloid elements have electrical conductivity intermediate between that of metals, which are good conductors, and nonmetals, which are whats?

Fluorine

The most electronegative element, what, is arbitrarily assigned an electronegativity value of four? Values for the other elements are then calculated in relation to this value

Highest

The order in which electrons are removed from all atoms of the d-block and f-block elements is exactly the reverse of the order given by the electron-configuration notation. In other words, electrons in the (lowest/highest) occupied sublevel are always removed first.

Main-group elements

The p-block elements together with the s-block elements are called the whats?

The Periodic law

The physical and chemical properties of the elements are periodic functions of their atomic numbers. Which law is this?

Less

The properties of the d-block elements (which are all metals) vary with what regularity than those of the main-group elements. (Hint: less or more)

Positive charge

The trend to smaller atoms (smaller atomic radii) across a period is caused by the increasing what of the nucleus?

Periodic table

The what is an arrangement of the elements in order of their atomic numbers so that elements with similar properties fall in the same column, or group?

Actinides

These are the 14 elements with atomic numbers from 90 (thorium, Th) to 103 (lawrencium, Lr).

Lanthanides

These are the 14 elements with atomic numbers from 58 (cerium, Ce) to 71 (lutetium, Lu).

Transition metals

These types of metals are typically less reactive than the alkali metals and the alkaline-earth metals. Some are so unreactive that they do not easily form compounds, existing in nature as free elements

Metalloids

These, or semiconducting elements, fall on both sides of a line separating nonmetals and metals in the p block. They are mostly brittle solids with some properties of metals and some of nonmetals

High reactivity

This ease of electron loss is a major reason for the what of the Group 1 (alkali) metals?

Electronegativity

This is a measure of the ability of an atom in a chemical compound to attract electrons

Linus Pauling

This man, one of America's most famous chemists, devised a scale of numerical values reflecting the tendency of an atom to attract electrons

Atomic radius

This may be defined as one-half the distance between the nuclei of identical atoms that are bonded together.

Increasingly

Thus, each successive electron removed from an ion feels an (increasingly/decreasingly) stronger effective nuclear charge (the nuclear charge minus the electron shielding).

Periodic

Today, Mendeleev's principle of chemical periodicity is correctly stated in what is known as the what law?

Closer

Valence electrons hold atoms together in chemical compounds. In many compounds, the negative charge of the valence electrons is concentrated in what relation to one atom than to another. This uneven concentration of charge has a significant effect on the chemical properties of a compound.

First: slight increase in nuclear charge down a group (increases electron affinities) Second: increase in atomic radius down group (decreases electron affinities)

What are the two reasons why electrons add with greater difficulty down a group? (In relation to electron affinity)

Ion

What is an atom or group of bonded atoms that has a positive or negative charge?

Nuclear charge, or the number of protons in the nucleus

When Henry Moseley examined the spectra of 38 different metals, he realized that the elements in the periodic table fit into patterns better when they were arranged in increasing order according to what or what?

Dmitri Mendeleev

When this Russian chemist heard about the new atomic masses discussed at Karlsruhe, he decided to include the new values in his chemistry textbook. He hoped to organize the elements according to their properties.

Transition elements

Which group of metals are good conductors of electricity and have a high luster?

Alkaline-earth metals

Which have higher melting points: Alkali metals or Alkaline-earth metals?

Periods

While the elements are arranged vertically in the periodic table in groups that share similar chemical properties, they are also organized horizontally in rows, or whats?

Attractive force isn't as strong because electrons are further away from the nucleus

Why is it easier to remove electrons as you go down a group?

Cations; Anions

Within each period of the periodic table, the metals at the left tend to form _____ and the nonmetals at the upper right tend to form _______