States of Matter and Properties

10 Questions

What type of model is the Earth-centered model?

Geocentric

What is the maximum sustainable population of a species in an ecosystem?

Carrying capacity

What is the characteristic of Mercury in our Solar System?

Closest to the Sun

What is the unit of distance from the Earth to the Sun?

Astronomical Unit

Why do meteors glow?

Due to friction with the atmosphere

What is the main characteristic of particles in a solid state?

They have a fixed shape and volume.

What is the purpose of grounding in discharging objects?

To neutralize electric charges

What is the difference between a series circuit and a parallel circuit?

A series circuit has one path, while a parallel circuit has multiple paths.

What is the role of decomposers in an ecosystem?

They break down dead organic matter into simple nutrients.

What is the main difference between a food chain and a food web?

A food chain is a linear sequence of who eats whom, while a food web is a complex network of interconnected food chains.

Study Notes

States of Matter

There are three states of matter: solid, liquid, and gas.
Particle Theory: matter is made up of particles that are always in motion, attract each other, and have space between them.
Particle movement increases with temperature.

Pure Substances and Mixtures

Pure Substances: have a fixed composition, examples include marble, distilled water, hydrogen, and silver.
Mixtures: have varying compositions, examples include soft drinks, brass, wood, vinegar, air, salt and water, soil, and cereal.

Density of Ice and Wood

Ice and wood have a density less than 1.0 g/mL, which is why they float on water.

Static Electricity

Static electricity is the buildup of electric charge on an object.
Law of Attraction and Repulsion: like charges repel, unlike charges attract.

Electric Circuits

Electric circuit components include conductors, insulators, and switches.
Circuit Behavior:
- Closed switch: current flows, bulbs light.
- Bulb #2 unscrewed: circuit open, bulbs before it stay lit.
- Bulb #5 unscrewed: circuit open, all bulbs go out.

Series and Parallel Circuits

Series circuits have one path, while parallel circuits have multiple paths.
Household wiring uses parallel circuits for safety.

Resistance Calculation

Resistance (R) can be calculated using the formula R = V/I (ohms).

Sustainable Ecosystems

A sustainable ecosystem is a self-sustaining community; examples of unsustainable areas include deforested regions.

Abiotic and Biotic Factors

Abiotic factors are non-living, such as sunlight and temperature.
Biotic factors are living, such as plants and animals.

Producer, Consumer, Decomposer

Producers: plants that make their own food.
Consumers: animals that obtain energy by consuming other organisms.
Decomposers: bacteria and fungi that break down organic matter.

Biodiversity

Natural ecosystems generally have more biodiversity than artificial ones.

Food Web vs. Food Chain

Food Web: interconnected food chains.
Food Chain: a linear sequence of who eats whom.

Invasive Species

Non-native species that cause harm to the ecosystem, such as zebra mussels.

Population Growth Curve and Carrying Capacity

Population growth curve shows changes over time.
Carrying capacity is the maximum sustainable population.

Bioaccumulation

The accumulation of toxins in organisms.

Space Exploration

Motion of Stars Models

Geocentric model: Earth-centered model.
Heliocentric model: Sun-centered model (accepted today).

Solar System

The Solar System consists of eight planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.

Terrestrial Planets

Characteristics of terrestrial planets, such as Mercury: closest to the Sun, no atmosphere.

Meteor Appearance

Glowing due to friction with the atmosphere.

Galaxy Types

Spiral galaxies: have arms.
Elliptical galaxies: oval shape.
Irregular galaxies: no specific shape.

Astronomical Unit vs. Light-Year

AU: distance from Earth to the Sun.
LY: distance light travels in a year.