Scientific Inquiry and Matter Concepts

Scientific Inquiry

• Scientific inquiry involves identifying patterns, evaluating hypotheses, assessing methods, and suggesting improvements.

Matter

• Matter is anything that occupies space and has mass.

Atom

• An atom is the smallest part of an element that retains the properties of that element.
• Atoms have a nucleus at the center containing protons and neutrons.
• Protons have a positive charge.
• Neutrons have no charge.
• Electrons, with a negative charge, orbit the nucleus.
• Atomic number = number of protons = number of electrons.
• Atomic mass = number of protons + number of neutrons (atomic mass is concentrated in the nucleus).

Substance

• A substance has a uniform composition.
• Compounds are composed of more than one kind of element.
• Elements are made up of a single kind of atom.

Properties

• Properties are characteristics used to describe substances.
• Physical properties can be observed or measured without changing the substance's identity (ex: mass, weight, volume, density, color, melting/boiling point, solubility, conductivity, magnetism).
• Size-dependent properties change with the size of the sample (ex: mass, weight, volume).
• Size-independent properties remain the same regardless of the sample size (ex: density, color, melting/boiling point, solubility, conductivity, magnetism).
• Weight is the pull of gravity on matter.
• Mass is the amount of matter in an object.

States of Matter

• Solids have a definite shape and volume.
• Liquids have indefinite shape but definite volume.
• Gases have indefinite shape and volume.
• Plasma is an ionized gas.

Changes of State

• Melting: solid to liquid.
• Evaporation: liquid to gas.
• Freezing: liquid to solid.
• Condensation: gas to liquid.
• Sublimation: solid to gas.

Chemical Changes

• A chemical change involves a substance changing into a different substance with new properties.
• Signs of a chemical change include color change, odor change, formation of bubbles, precipitate formation, light emission (or absorption), or temperature change.
• Chemical reactions produce new substances.

Mixtures

• Mixtures are substances composed of two or more different components not chemically bonded.
• Heterogeneous mixtures' components are not evenly distributed (ex: fruit salad).
• Homogeneous mixtures are uniform, their components mixed evenly (ex: tea with sugar).

Separating Mixtures

• Methods for separating mixtures (filtration, evaporation, etc).

Ecology

• Symbiosis: a long-term close relationship between two species (mutualism, commensalism, parasitism).
• Cooperative relationships (predator-prey relationships).
• Biotic factors: living things (plants, animals, humans).
• Abiotic factors: non-living things (sun, water, soil, rocks).
• Limiting factors: anything that restricts population growth.
• Ecosystem: the living and non-living things in an area and their interaction.

Population and Community

• Population: all the organisms of the same species that live in the same area at the same time.
• Species: a group of organisms that can interbreed and produce fertile offspring.
• Community: all the populations of different species that live together in the same area at the same time.
• Biosphere: the parts of Earth and the surrounding atmosphere where life exists.

Ecological Succession

• Ecological succession: the gradual change in a community over time.
• Primary succession: occurs in areas with no soil, pioneer species first.
• Secondary succession: occurs in areas with existing soil, such as after a fire.
• Climax community: a stable community that has reached its final stage of succession.

Ecosystem Changes

• Environmental changes, natural disasters, and human activities can cause shifts in ecosystems.