First Semester Final Exam - Review-1 Fall 2024.docx

What is chemistry?

The study of matter and the changes it undergoes.

What are the five branches of chemistry?

Organic, inorganic, physical, analytical, and biochemistry.

What evidence implies a chemical reaction has occurred?

Gas evolution, precipitate formation, color change, temperature change, odor change, sound production, or change in taste.

Define a physical property vs. a chemical property.

A physical property can be observed without changing the substance, while a chemical property describes how a substance reacts.

What is the difference between a physical change and a chemical change?

A physical change alters a substance without changing its composition; a chemical change results in a new substance.

Classify boiling water: physical or chemical?

Physical change.

Classify rusting iron: physical or chemical?

Chemical change.

Classify burning candles: physical or chemical?

Chemical change.

Classify breaking glass: physical or chemical?

Physical change.

Classify melting wax: physical or chemical?

Physical change.

What is an extensive property?

A property that depends on the amount of matter present.

What is an intensive property?

A property that depends on the type of matter, not the amount.

Identify lead: element, compound, or mixture?

Element.

Identify water: element, compound, or mixture?

Compound.

Identify Kool-Aid: element, compound, or mixture?

Mixture.

What are the characteristics of a metal?

Good conductors of heat and electricity, malleable, ductile, high luster.

What are the characteristics of a non-metal?

Poor conductors, brittle in solid form, varied appearance.

What are the characteristics of a metalloid?

Intermediate properties between metals and nonmetals; semiconductors.

What is Dalton's Atomic Theory?

Matter is composed of atoms, which are indivisible; atoms of a given element are identical in mass and properties; compounds are formed by combining different types of atoms.

What did Rutherford's Gold Foil Experiment reveal?

The existence of a small, dense nucleus at the center of atoms.

What did J. J. Thomson discover?

The electron, using the Cathode Ray experiment.

Define atomic number.

The number of protons in an atom.

Define mass number.

The total number of protons and neutrons in an atom.

Define average atomic mass.

The weighted average of the masses of the isotopes of an element.

What are isotopes?

Atoms of the same element that have the same number of protons but different numbers of neutrons.

What is the Law of Conservation of Mass?

Mass is neither created nor destroyed in a chemical reaction.

What is the principal quantum number?

The number that indicates the main energy level occupied by electrons.

What occurs when an electron moves to a lower energy level?

It releases energy, often in the form of light.

What is a chemical bond?

The force that holds atoms together in a compound.

What are valence electrons?

Electrons in the outermost shell of an atom that participate in chemical bonding.

State the octet rule.

Atoms tend to gain, lose, or share electrons to achieve a full outer shell of eight electrons.

What is VSEPR theory?

Valence Shell Electron Pair Repulsion theory; it predicts molecular geometry based on electron pair repulsion.

What is the formula for phosphoric acid?

H3PO4.

Name the following acid: HCl.

Hydrochloric acid.

What is the chemical formula for potassium chlorite?

KClO2.

What is the formula for iron(III) sulfide?

Fe2S3.

What is the formula for lithium carbonate?

Li2CO3.

What do the columns in the periodic table represent?

Groups or families with similar chemical properties.

Which element has similar chemical properties to Si?

Carbon (C), due to being in the same group.

What color of light has the most energy?

Violet light.

How many total electrons can occupy an s orbital?

2 electrons.

An ion of an element has 29 protons, 35 neutrons, and 27 electrons. What is the ion and its symbol?

Copper (Cu) 2+, indicating it lost 2 electrons.