2B1 Organization of Matter Flashcards
Explore how matter is organized into substances, mixtures, states of matter, and smaller units of atoms, ions, and molecules.
List the four states of matter.
- Solid
- Liquid
- Gas
- Plasma
These states differ in energy, density, and the behavior of their molecules.
Plasma, while rare on Earth, is the most abundant state in the universe.
What characteristics define a solid state of matter?
- Definite shape
- Definite volume
- Tightly packed molecules
The molecules in solids vibrate in place but do not move freely, resulting in high density and low energy.
Fill in the blank:
Liquids have a/an _______ shape.
indefinite
Particles in a liquid are loosely packed and flow freely, allowing liquids to take the shape of their container.
The moderate energy of liquids enables this movement while maintaining a fixed volume.
What state of matter has the highest energy?
Plasma
The energy of this gas-like substance comes from the free electrons and positively charged ions. Found in the sun and lightning, this forms at high temperatures when electrons are stripped from atoms. It has no definite shape or volume and is electrically conductive.
List two characteristics of gases.
- Indefinite shape
- Indefinite volume
The molecules in gases move freely and are widely spaced due to high energy.
Define:
phase transition
The process of matter changing from one state to another, such as melting or freezing.
Phase transitions occur when energy is added or removed from a substance.
During melting, a solid absorbs energy and changes into a liquid.
During freezing, a liquid loses energy and changes into a solid.
What happens to the density of matter as it changes from solid to gas?
It decreases.
This is because the molecules move further apart as energy increases.
What transition occurs when a gas becomes a liquid?
Condensation
This occurs when a gas loses heat energy and molecules come closer together.
Example: Water droplets forming after boiling.
What is the difference between sublimation and deposition?
- Sublimation: Direct transition from solid to gas.
- Deposition: Direct ransition from gas to solid.
Both bypass the liquid phase entirely.
Sublimation example: Dry ice turning into carbon dioxide gas.
Deposition example: Frost forming on cold surfaces.
What is an atom?
The smallest unit of matter that retains the identity of an element.
Atoms are the fundamental building blocks of matter.
They consist of protons, neutrons, and electrons.
Define:
ions
Positively or negatively charged atoms or molecules.
Ions are formed when atoms gain or lose electrons.
What is the charge of a neutral atom?
0
A neutral atom has an equal number of protons and electrons.
What particles make up the nucleus of an atom?
Protons and neutrons
Protons are positively charged, while neutrons carry no charge.
What is the difference between cations and anions?
- Cations: Positively charged.
- Anions: Negatively charged.
Cations are formed when an atom loses electrons while anions are formed when atoms gain electrons.
What are monoatomic ions?
Ions made up of one atom.
Examples include H+ (cation) and Cl− (anion).
What are polyatomic ions?
Ions made of more than one atom.
The atoms are bonded together.
Examples include OH− (anion) and NH3+ (cation).
What type of bond is formed between cations and anions?
Ionic bonds
Ionic bonds are electrostatic attractions between charged ions.
What is the difference between atomic mass and mass number?
- Atomic mass: The weighted average of all the isotopes of an element.
- Mass number: The sum of protons and neutrons in the nucleus of an atom.
Both are used to describe the nucleus of an atom.
What is a molecule?
A structure made of two or more atoms bonded together.
Molecules are formed through chemical reactions.
How are atoms related to molecules?
Atoms are the building blocks of molecules.
Atoms bond by donating or sharing electrons.
What is a compound?
A type of molecule made of two or more different elements.
Not all molecules are compounds.
What distinguishes a compound from a molecule?
A compound consists of different elements bonded together, while a molecule consists of similar elements bonded together.
For example, carbon dioxide (CO2) is a compound, while molecular oxygen (O2) is not.
What are the two main types of chemical bonds?
- Ionic bonds
- Covalent bonds
These bonds form molecules and compounds, with ionic bonds being stronger than covalent bonds. Other kinds of chemical bonds include metallic bonds, hydrogen bonds, and Van der Waals interactions.
What occurs in ionic bonds?
Electrons are donated between atoms with different electronegativities.
This results in charged atoms (cations and anions).
What occurs in covalent bonds?
Electrons are shared between atoms with relatively equal electronegativities.
Covalent bonds typically form between nonmetals.
Define:
mixture
A physical blend of two or more substances where components retain their original properties.
Mixtures can be separated into their component parts.
Give an example of a mixture.
Seawater: A mixture of salts and water.
Each component in a mixture retains its own chemical properties.
Other examples:
- Crude oil: A mixture of organic compounds (mainly hydrocarbons).
- Air: A mixture of various gases like oxygen, carbon dioxide, nitrogen, argon, neon, etc.
- Ink: A mixture of coloured dyes.
- Gunpowder: A mixture of sulfur, potassium nitrate and carbon.
What are the two categories of mixtures?
- Homogeneous
- Heterogeneous
Homogeneous mixtures have evenly distributed components, while heterogeneous mixtures do not.
Salt water solution is a homogeneous mixture while suspensions and colloids are heterogenous mixtures.
Define:
a solution
A homogenous mixture where solids dissolve into a liquid.
Examples: Saltwater, sugar in water, and a cup of coffee.
Define:
an alloy
A solid homogeneous mixture of elements, at least one of which is a metal.
Steel, an alloy of iron and carbon, is a common example.
What is a suspension?
A heterogeneous mixture where solid particles do not dissolve in a liquid and settle over time due to gravity.
Suspensions differ from solutions because their particles are larger and visible, making them easy to separate.
Examples:
- Muddy water
- Chalk in water
- Hot cocoa
What is the size range of particles in a suspension?
500 to1000 nanometers
These large particles are why suspensions are cloudy and can be separated by filtration.
What is the size range of particles in a colloid?
2 to500 nanometers
Colloidal particles are larger than in a solution but smaller than in a suspension, making them stable.
What does it mean if a mixture is opaque?
It does not allow light to pass through, typical of suspensions and some colloids.
Suspensions appear opaque because the large particles scatter or block light. Examples include blood or hot chocolate.
What is the difference between a colloid and a suspension?
- Colloid: Particles do not settle over time.
- Suspension: Particles settle over time due to gravity.
Colloids are stable mixtures where particles are dispersed but too small to settle, unlike suspensions.
Milk is an example of a colloid.
