Foundations of Chemistry: Basic Concepts of Matter and Energy

50 practice flashcards covering key concepts from basic chemistry concepts, matter, energy, measurement, units, density, significant figures, and dimensional analysis.

What is matter?

Matter is anything that has mass and takes up space.

Name the four common phases of matter and a defining feature of each.

Solid: fixed volume and shape; Liquid: fixed volume but takes shape of container; Gas: no fixed volume or shape; Plasma: high-temperature state with mobile charged particles.

What are the characteristics of a solid?

Fixed volume and fixed shape.

What are the characteristics of a liquid?

Fixed volume but no fixed shape; it takes the shape of its container.

What are the characteristics of a gas?

No fixed volume or shape; it expands to fill its container.

What is plasma and where is it typically found?

A high-temperature phase with mobile charged particles; found in stars, neon signs, and plasma TVs.

What is mass?

A measure of the amount of matter in an object.

What is weight?

The force gravity exerts on an object.

How does mass on Earth compare to mass on the Moon?

Mass is the same on Earth and the Moon; weight differs due to gravity.

State the Law of Conservation of Matter.

There is no change in the total quantity of matter when matter is converted from one form to another.

What is a pure substance?

A substance with distinct properties and composition that does not vary from sample to sample.

What is an element?

A substance that cannot be broken down by chemical means.

What is a compound?

A substance that can be broken down into simpler substances by chemical means; composed of two or more different elements.

In the mercury(II) oxide example, what happens when heated?

It decomposes into liquid mercury droplets and oxygen gas.

What is an atom?

The smallest particle of an element that retains the properties of that element.

What is a molecule?

Two or more atoms joined by chemical bonds.

What is a homogeneous mixture?

A mixture with uniform composition throughout; also called a solution.

What is a heterogeneous mixture?

A mixture with nonuniform composition; varies throughout.

Give an example of a heterogeneous mixture.

Oil and vinegar salad dressing.

Give an example of a homogeneous mixture.

A commercial sports drink.

Is carbon an element, compound, or mixture?

Element.

Is air an element, compound, or mixture?

Homogeneous mixture.

Is water an element, compound, or mixture?

Compound.

Is glucose (C6H12O6) an element, compound, or mixture?

Compound.

Is salt water an element, compound, or mixture?

Homogeneous mixture (solution).

Is granite an element, compound, or mixture?

Heterogeneous mixture.

Is nitrogen (N2) an element or a compound?

Element.

What is the difference between physical and chemical properties?

Physical properties do not involve changing the chemical composition; chemical properties describe how a substance can change into new substances.

What are examples of physical properties?

Boiling point, density, mass, and volume.

What is a physical change?

A change in state or properties without changing the chemical composition.

What is a chemical change?

A process that results in the formation of new substances.

Give examples of chemical properties.

Flammability, corrosiveness, or reactivity with acid.

What is an extensive property?

A property that depends on the amount of substance present (e.g., mass, volume, energy).

What is an intensive property?

A property that is independent of the amount of substance present (e.g., density, boiling point, color).

Is the statement 'The total volume of water is 150 mL' extensive or intensive?

Extensive.

When hydrogen burns in oxygen, is it a physical or chemical property, and is it extensive or intensive?

Chemical and intensive.

What is energy in general terms?

The capacity to do work or to supply heat.

What is kinetic energy?

Energy possessed by an object due to its motion.

What is potential energy?

Energy stored due to position or arrangement.

State the Law of Conservation of Energy.

Energy cannot be created or destroyed in a chemical or physical change, only transformed.

What is the unit of energy?

Joule (J), defined as kg·m^2/s^2.

What are the SI base units for mass, length, time, temperature, and amount?

Mass: kilogram (kg); Length: meter (m); Time: second (s); Temperature: Kelvin (K); Amount: mole (mol).

What is a derived unit?

A unit formed by combining base units (e.g., volume in m^3, density in kg/m^3).

List common SI prefixes and their powers of ten.

tera 10^12; giga 10^9; mega 10^6; kilo 10^3; deci 10^-1; centi 10^-2; milli 10^-3; micro 10^-6; nano 10^-9; pico 10^-12.

What mnemonic helps remember metric prefixes, and what does it stand for?

The Great Man King Henry’s Daughter Beth drinks cold milk until nine pm; stands for Tera, Giga, Mega, Kilo, Hecto, Deca, Deci, Centi, Milli, Micro, Nano, Pico.

Convert 37.6 cm to millimeters.

376 mm.

What is the formula for density?

D = m / V.

What are common density units?

kg/m^3, g/mL, and other equivalent units.

What are significant figures?

Digits that carry meaning about the precision of a measurement; nonzero digits are significant; zeros rules depend on decimal points; exact numbers have infinite significant figures.

What are the rules for handling zeros in significant figures?

Leading zeros are not significant; captive zeros are significant; trailing zeros are significant if there is a decimal point.

What are the rules for rounding in addition and subtraction?

Round to the least number of decimal places among the numbers used.

What are the rules for rounding in multiplication and division?

Round to the least number of significant figures among the numbers used.

What is the difference between accuracy and precision?

Accuracy is how close a measurement is to the true value; precision is how close repeated measurements are to each other.

What is systematic error?

An observable pattern in measurements (consistent bias).

What is random error?

Measurements do not show an observable pattern (unpredictable variation).

What is dimensional analysis used for?

Converting between units using equivalence factors.

What is a base unit in dimensional analysis?

A fundamental unit (e.g., meter, kilogram, second, mole, kelvin).

What is a derived unit in dimensional analysis?

A unit formed by combining base units (e.g., m^3, kg/m^3).

What does volume measure and what are its base units?

Volume measures space occupied; base unit is liter (L) or cubic meters (m^3).

How many centimeters are in a meter?

100 cm = 1 m.

What is the Fahrenheit to Celsius conversion formula?

ToC = 5/9 (°F – 32).