Chemistry Foundations: Matter, Atomic Theory, Bonding, and Measurements

A set of practice flashcards covering core concepts from matter, atomic theory, properties, mixtures, periodic table basics, separation methods, and introductory chemistry topics.

What is matter?

Matter is anything that has mass and occupies volume.

What is the difference between mass and weight?

Mass is the amount of matter; weight is the gravitational pull on matter.

Name the common states of matter.

Solid (definite shape/volume), Liquid (definite volume), Gas (no definite shape/volume), Plasma (hot ionized gas), and Bose-Einstein Condensate (near-zero temperature state).

What is plasma?

A hot ionized gas consisting of approximately equal numbers of positively charged ions and electrons.

What is a Bose-Einstein Condensate?

A state where atoms or subatomic particles are cooled to near absolute zero, behaving as a single quantum entity.

State Dalton’s Atomic Theory in brief.

Matter is composed of atoms; atoms of a given element differ; compounds are fixed whole-number ratios of atoms; atoms rearrange but are not created or destroyed in reactions.

What does the Law of Conservation of Mass state?

Mass is conserved in chemical reactions; matter is not created or destroyed.

Who proposed the Law of Conservation of Mass?

Antoine Lavoisier.

What does the Definite Proportions law state?

Elements combine in fixed whole-number ratios to form compounds.

What does the Multiple Proportions law state?

When two elements form more than one compound, the masses of one element that combine with a fixed mass of the other are in simple whole-number ratios.

What is a physical property?

A property observed without changing the substance.

What is the difference between intensive and extensive physical properties?

Intensive properties do not depend on amount (e.g., density, color, boiling/melting point); extensive properties do depend on amount (e.g., mass, volume).

What is a chemical property?

Properties observed during chemical change, such as combustibility, stability, reactivity, relative activity, ionization, and toxicity.

Define combustibility.

Whether a substance can undergo combustion.

Define stability.

Whether a substance easily decomposes or remains intact under given conditions.

Define reactivity.

Whether a substance reacts with acids, bases, or oxygen.

Define relative activity.

Whether materials are more active or less active in reactions.

Define ionization.

Whether a substance will break into charged particles when in solution with water.

Define toxicity.

Whether a substance can damage an organism.

What is a Pure Substance?

A substance with constant composition.

What is an Element?

A substance consisting of one kind of atom.

What is a Compound?

A substance formed by chemically combined elements.

What is a Heterogeneous mixture?

A mixture that is not uniform throughout (e.g., sand and salt).

What is a Homogeneous mixture?

A uniform mixture; also called a solution.

What is Atomic Number Z?

The number of protons in an atom.

What is Mass Number A?

The total number of protons and neutrons in the nucleus.

How do you calculate neutrons?

Neutrons = A − Z.

What are Groups and Periods in the periodic table?

Groups are columns; Periods are rows.

What are Metals?

Metals are typically conductors, malleable, and ductile.

What are Nonmetals?

Nonmetals are typically poor conductors and brittle.

What are Metalloids?

Elements with properties between metals and nonmetals; often semiconductors.

Why are Metalloids called semiconductors?

Because they have intermediate electrical conductivity useful in electronics.

What is Decantation?

Pouring off liquid after allowing solids to settle.

What is Magnetic Separation?

Using magnetic properties to separate components of a mixture.

What is Filtration?

Separation of components of a suspension using a filter.

What is Evaporation?

The process of turning a liquid into a gas to separate components.

What is Distillation?

Separates a homogeneous mixture based on differences in boiling points.

What is Chromatography?

Separates components of a complex mixture based on differences in movement through a medium.

What is Sublimation?

Solid to gas transition without passing through the liquid phase.

What is Centrifugation?

Spins a mixture so that sediments settle to the bottom, allowing liquid to be poured off.