chem q 1

Science

Systematic study of the natural world through observation and experimentation.

Chemistry

Study of matter, its properties, and changes.

Technology

Application of scientific knowledge for practical purposes.

Green Chemistry

Reduces or eliminates hazardous substances.

Sustainable Chemistry

Meets present needs without harming future generations.

Hypothesis

Testable explanation or prediction.

Scientific Law

Statement summarizing repeated observations (what happens).

Scientific Theory

Well-tested explanation of phenomena (why it happens).

Scientific Model

Representation of a process or object.

Risk

Probability of harm or loss (e.g., chemical irritates skin).

Benefit

Positive outcome or gain (e.g., chemical cleans effectively).

Desirability Quotient (DQ)

Formula: DQ = Benefit / Risk.

Basic Research

Fundamental knowledge without immediate application (e.g., atomic structure).

Applied Research

Solves practical problems (e.g., developing medicines).

Mass

Amount of matter (kg, g). Example: 10 kg rock.

Weight

Force of gravity (N). Example: 98 N on Earth.

Physical Change

Alters appearance, not composition. Example: Ice melting.

Chemical Change

Alters composition. Example: Iron rusting.

Physical Property

Observed without changing substance. Example: Color, density.

Chemical Property

Potential chemical change. Example: Flammability.

State of Matter

Solid, Liquid, Gas.

Composition

Element, Compound, Mixture.

Homogeneity

Homogeneous (uniform) vs Heterogeneous (not uniform).

Density

Density = Mass / Volume.

Units of Mass

Measured in grams (g) and kilograms (kg).

Volume Units

Measured in milliliters (mL), liters (L), and cubic centimeters (cm³).

Heat

Total energy of particle motion (Joules).

Temperature

Average kinetic energy of particles (°C, K, °F).

Temperature Conversion to Kelvin

Kelvin = °C + 273.15.

Temperature Conversion to Fahrenheit

°F = °C × 9/5 + 32.

Temperature Conversion from Fahrenheit

°C = (°F - 32) × 5/9.

Critical thinking s 1

Identify the claim

Critical thinking S2

Examine the evidence

Critical thinking S3

Check for bias or assumptions

Critical thinking s4

Determine logic and consistency

Critical thinking s5

decide if claim is valid or needs testing