Chem 210: Chapter 2 Book

Front 1

What is an atom?

Back 1

It is the basic building block of matter composed of a nucleus and an electron cloud.

Front 2

What is the periodic table?

Back 2

A schematic arrangement of all known elements that groups elements with similar properties.

Front 3

What are metals?

Back 3

They are shiny materials that are good conductors of heat and electricity. All are solids at room temperature except for mercury, which is a liquid.

Front 4

What are nonmetals?

Back 4

They do not have a shiny appearance, and they are generally poor conductors of heat and electricity. They come in all forms, solid, liquid, and gas.

Front 5

What are metalloids?

Back 5

They have properties intermediate between metals and nonmetals. Only seven elements are categorized as this: boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te), and astatine (At)

Front 6

What are the building-block elements?

Back 6

Oxygen, Carbon, Hydrogen, Nitrogen.

Front 7

What are major minerals/macronutrients?

Back 7

Seven other elements found in the body in much smaller amounts. At least 100 mg of each is needed daily.

Front 8

What are trace elements/micronutrients?

Back 8

They are in very small amounts in the body and required in the daily diet in small quantities.

Front 9

What is a chemical formula?

Back 9

It uses element symbols to show the identity of the elements forming a compound and subscripts to show the ratio of atoms contained in the compound.

Front 10

What is a nucleus?

Back 10

It is a dense core that contains the protons and neutrons. Most of the mass of an atom resides in this.

Front 11

What is an electron cloud?

Back 11

It is composed of electrons that move rapidly in the almost empty space surrounding the nucleus. It comprises most of the volume of an atom.

Front 12

What is an atomic mass unit (amu)?

Back 12

It equals one-twelfth the mass of a carbon atom that has six protons and six neutrons; 1 = 1.661 x 10^-24 g.

Front 13

What is atomic number (Z)?

Back 13

The number of protons in the nucleus of an atom.

Front 14

What is an isotope?

Back 14

It is an atom of the same element having a different number of neutrons.

Front 15

What is atomic weight/atomic mass?

Back 15

It is the weighted average of the mass of the naturally occurring isotopes of a particular element reported in atomic mass units.

Front 16

What is a period?

Back 16

A row on the periodic table. Elements are similar in size.

Front 17

What is a group?

Back 17

It is a column on the periodic table. Elements have similar electronic and chemical properties.

Front 18

What are the main group elements?

Back 18

They consist of the two columns on the far left and the six columns on the far right of the table. These groups are numbered 1A-8A.

Front 19

What are the transition metal elements?

Back 19

They are contained in the 10 short columns in the middle of the table, numbered 1B-8B.

Front 20

What are inner transition metal elements?

Back 20

They consist of the lanthanides and actinides, and they are not assigned group numbers.

Front 21

What are alkali metals?

Back 21

They are located in group 1A, included lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr). They are soft and shiny and have low melting points. They are good conductors of heat and electricity. They react readily with water to form basic solutions.

Front 22

What is are alkaline earth elements?

Back 22

They are located in group 2A. They include beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra). They are shiny solids but less reactive than the alkali metals.

Front 23

What are halogens?

Back 23

They are located in group 7A (group 17), include flourine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At). In their elemental form they contain two atoms joined together. They are very reactive and combine with many other elements to form compounds.

Front 24

What are noble gases?

Back 24

They are located in group 8A (group 18), include helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn). They are especially stable as atoms, and so they rarely combine with other elements to form compounds.

Front 25

Describe principal energy levels/shells?

Back 25

- They are numbered, n = 1, 2, 3, 4, and so forth, beginning closet to the nucleus.

- Electrons closer to the nucleus are held more tightly are lower in energy

- Electrons farther from the nucleus are held less tightly and are higher in energy

Front 26

What is an orbital?

Back 26

It is a region of space where the probability of finding an electron is high Each can hold two electrons. They are identified by letters s (1), p (3), d (5), and f (7).

Front 27

What are the rules to determine the ground states electronic configuration of an atom?

Back 27

1. Electrons are placed in the lowest energy orbitals beginning with the 1s orbital.

- In comparing similar types of orbitals from one shell to another an orbital closer to the nucleus is lower in energy. Thus, the energy of a 1s orbital is lower than a 2s orbital.

- Within a shell, orbital energies increase in the following order: s, p, d, f

- These guidelines result in the following order of energies in the first three periods: 1s, 2s, 2p, 3s, 3p.

2. Each orbital holds a maximum of two electrons.

Front 28

What are valence electrons?

Back 28

The electrons in the outermost shell.

Front 29

How are valence electrons related to group number?

Back 29

- Elements in the same group have the same number of valence electrons and similar electronic configurations.

- The group number (using the 1A-8A system) equals the number of valence elctrons to main group elements (except helium).

Front 30

Explain the electron-dot symbols?

Back 30

- Each dot represents one valence electron.

- The dots are placed on the four sides of an element symbol

- For one to four valence electrons, single dots are used. With more than four electrons, the dots are paired.

Front 31

Explain the periodic trend with atomic size?

Back 31

- The size of atoms increases down a column of the periodic table, as the valence electrons are farther from the nucleus.

- The size of atoms decreases across a row of the periodic table as the number of protons in the nucleus increases. An increasing number of protons pulls the electrons closer to the nucleus, so the atom gets smaller.

Front 32

Explain the periodic trend with ionization energy?

Back 32

- Ionization energies decrease down a column of the periodic table as the valence electrons get farther from the positively charged nucleus.

- Ionization energies generally increase across a row of the periodic table as the number of protons in the nucleus increases.

Front 33

What is ionization energy?

Back 33

The energy needed to remove an electron from a neutral atom.

Front 34

What is a cation?

Back 34

A positively charged ion, and has fewer electrons than the neutral atom.

Front 35

What is an anion?

Back 35

A negatively charged ion, and has more electrons than the neutral atom.