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Question 1

These are the electrons located at the outermost (highest) principal energy level of a representative or noble gas element.

Assigning valence electrons is only applicable to representative elements, that is, groups IA to VIIIA (transition elements in the d sublevels are NOT included)

It is, therefore, common to see valence electrons in the s or p sublevels.

Answer 1

Valence Electrons

Question 2

The electrons located between the valence electrons and the nucleus are called core electrons. In other words, all the other electrons which are not found in the outermost shell are considered core.

Answer 2

Core electrons

Question 3

is also called Lewis Dot Diagram or Lewis symbol.

Gilbert Lewis, an American chemist, first introduced this shorthand symbol

devised by scientists to designate the valence electrons of the atoms in an element

Answer 3

Lewis Dot Diagram

Question 4

have complete outermost electrons.

Answer 4

noble gases

Question 5

the maximum number of valence electrons for any element

Answer 5

eight

Question 6

This rule states that the atoms of an element lose, gain or even share electrons so that their electron configurations achieve eight valence electrons.

This will be the basis for the next topic, chemical bonds.

Answer 6

octet rule

Question 7

A force that holds groups of two or more atoms together and makes them function as an intact unit.

Answer 7

chemical bond

Question 8

Bonds involve the electrons in the

Answer 8

outer shells of atoms

Question 9

The atoms of noble gases have full outer shells and so are stable.

Answer 9

This makes the noble gases very unreactive, and so they do not usually form bonds.

Question 10

The atoms of other elements have incomplete outer electron shells making them unstable.

Question 11

are formed when different elements chemically react with each other.

Answer 11

compounds

Question 11

occurs between nonmetals atoms only

Answer 11

covalent bonding

Question 12

occurs between metal and nonmetal atoms.

Answer 12

ionic bonding

Question 13

occurs between metal atoms only

Answer 13

metallic bonding

Question 14

All bonds involve electrons, and all bonding includes changes in the number of valence electrons.

Question 15

metal is at the right side

Answer 15

non metal left side kasama yung H

Question 16

For a substance or mixture to conduct electricity

It must contain charged particles.
Charged particles must be free to move or migrate.

Answer 16

conductivity

Question 17

Ionic compounds are always electrolytes if they DISSOLVE in water

Question 17

A type of chemical bond due to the attractive electrostatic force between cations (+ metal) and anions (- nonmetals)

Electrostatic forces: attraction/repulsion that exists between charged particles.

Answer 17

Ionic bonding

Question 18

Electrolyte - conducts electricity - release ions when dissolved in water (dissociation or ionization)

Answer 18

Non-electrolyte- does not conduct electricity- no mobile or dissociated ions

Question 19

are due to the sharing of electrons by two (or more) nonmetal atoms.

Answer 19

covalent bonding

Question 20

form when one atom “TRANSFERS” an electron with another atom.

is the electrostatic force that holds OPPOSITE CHARGES in a compound: METAL(cation, +) and NONMETAL(anion -)

Answer 20

Ionic Bond

Question 20

is an atom or molecule that is positively (+) or negatively (-) charged

is created when a neutral atom accepts or donates one or more electrons.

Answer 20

Ion

Question 21

The collective set of rules that help you name chemical formulas is known as

Answer 21

nomenclature

Question 22

CASE 1: Representative metal + nonmetal

Answer 22

When naming binary compounds, the following rules apply: In the compound name, metal cations are named the same as on the periodic table, while anions change their ending to –ide. Cations are always written first in an ionic formula, followed by the anion. General pattern: metal name + nonmetal name (-ide) For example, in NaCl, the Na cation keeps its name – sodium – while the anion changes from chlorine to chloride.

Question 23

The crisscross method: Writing the Chemical Formula of Binary Ionic Compounds

Answer 23

Ionic compounds must be electrically neutral therefore, the total amount of positive and negative charge must be the same. This is the rule that determines how many of each ion species are needed in the chemical formula. The crisscross method uses ion charges to determine how many of each ion must be present in the neutral chemical formula.

Question 24

CASE 2: Transition metal + nonmetals

Answer 24

Copper, for example, can form an ion with either a 1+ or a 2+ charge. In the table below, there are several names for monatomic cations followed by a Roman numeral. A Roman numeral specifies which charge the ion should have when naming the compound or crisscrossing to write the formula. When you see a cation with Roman numeral 3, III, the ion’s charge is 3+. When you see a cation with II, the charge is 2+, and so on. Transition metals are the elements that belong to the d-block, and they can have multiple charges. There are two methods in naming transition metals in a compound: 1. IUPAC (International Union of Pure and Applied Chemistry) name or Modern Stock System Some metals always form the same ion with the same charge, but many metals can form ions with different charges. Makes use of Roman numerals (indicate the ion charge) 2. Traditional or Old Stock System element root name + ous ending: refers to the ion with a lower charge. element root name + ic ending: refers to the ion with a higher charge. Table 1. Some transition metals and their old and modern names. RULES: General pattern: transition metal name (Stock/Traditional) + nonmetal name (-ide) The metal names are always written first The ending of the nonmetal is replaced with “-ide” Examples: 1. CuCl First, determine the charge of Cu used in the compound. Since Cl has no subscript, it means that the charge of Cu that was used is 1+. Similar to case 1, the transition metal name is retained but the suffix of the nonmetal will be changed to -ide. Stock name (Modern): Copper (I) chloride Traditional name: Cuprous chloride 2. FeCl3 Determine the charge of Fe used in the compound. Since Cl has a subscript of 3, it means that the charge of Fe that was used is 3+. If we look at the table, we will use Iron (III) as the modern name, and Ferric as the traditional name. Stock name (Modern): Iron (III) chloride Traditional name: Ferric chloride B. The Covalent Bond Covalent bonds form between atoms that are identical or close to each other on the periodic table, usually in non-metals. The bonds between hydrogen and oxygen atoms in H O are covalent bonds. Each covalent bond is a single shared electron pair. Covalent bonds are local - they connect two specific atoms. Involves nonmetals To attain stability, the electrons are shared Sharing of 1 or more valence electrons form a chemical bond known as covalent bonds

Question 25

CASE 3: Non-metals

Answer 25

Let’s look at binary covalent compounds. Binary covalent compounds have a simple naming procedure: Use the same rules for naming simple binary ionic compounds. Add a prefix to each name that indicates how many of that atom are in the molecule. If there is only one atom of the first element in the chemical formula, leave out the “mono” prefix. This rule applies only to the first element in the formula.

Question 26

is a compound made of only two atoms with a covalent bond. Carbon monoxide, CO, is a diatomic molecule made of two different atoms. Oxygen gas, O2, is a diatomic molecule made of two of the same atoms.

Answer 26

Diatomic Molecules

Question 27

7 elements that form diatomic molecules

Answer 27

There are seven elements on the periodic table that are found in nature in their pure form bonded to each other as a diatomic molecule. These seven elements are: hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine, and iodine. The seven are all non-metals, they exist as gases at room temperature, and they have the chemical formula X2 where X represents their element symbol: H2, N2, O2, F2, Cl2, Br2, I2. When you are told one of these elements is involved in a chemical reaction, you must assume it is in its diatomic form, not its elemental or atom form.