What is the scientific method?
The technique for testing ideas by making observations and gathering evidence.
What are the steps of the scientific method?
- Making observations
- Ask questions
- Develop a hypothesis
- Make predictions
- Test the predictions
- Analyze and interpret results
Manipulative experiments
Experiments where the researcher chooses and manipulates the independent variable.
Natural Experiments
Experiments where the thing that’s being tested is exposed to the experimental and control conditions that are determined by nature and are out of the researchers’ control.
What is a theory?
A widely accepted, well-tested explanation of one or more cause-and-effect relationships, which has been validated by extensive research.
What is matter?
All the material in the universe that has mass and occupies space.
The law of conservation of matter
Matter can be transformed from one type of substance into another, but it can’t be created or destroyed.
Element
An element is a chemical substance with a given set of properties that is made of atoms. (ex// oxygen)
Atoms
The smallest components that maintain an element’s chemical properties.
What do atoms consist of? What are they defined by?
Protons (+), electrons (-), and neutrons (neutral). They are defined by the number of protons they have.
What are isotopes?
Atoms of the same element with the same number of protons, but different number of neutrons.
Radioactive isotopes
Isotopes that decay over time in predictable ways and release energy (high-energy radiation) and shed subatomic particles.
Molecules
Molecules are formed when 2 or more of the same atoms bond. (ex// O2)
Compounds
Made up of different elements (ex// H2O)
Solutions
Mixtures of 2 or more substances.
What are water’s properties? Give a brief description of why they’re important.
- Water remains liquid over a wide range of temperatures –> because of this water-based biological processes can occur in a wide range of environmental conditions.
- Water exhibits strong cohesion –> gives water molecules the ability to stick to each other –> surface tension
- Adhesion –> water molecules bond well with other polar molecules
- Water has a high heat capacity –> absorbs large amount of heat with small changes in its temperature –> stabilizes systems against change
- Water molecules in ice are farther apart than in liquid water –> floating ice has an insulating effect that can prevent water bodies from freezing solid
- Fresh water reaches its maximum density at 4 degrees
- Water is the universal solvent
- Water is transparent to light –> makes photosynthesis possible
Organic compounds
Carbon-based compounds joined by covalent bonds.
What are the 4 macromolecules that are essential to life?
Proteins, nucleic acids, carbohydrates and lipids.
Energy
The capacity to change the position, physical composition, or temperature of matter. It is a force that can accomplish work and is the driver of Earth’s environmental processes.
Potential energy
Energy of position.
Kinetic energy
Energy of motion.
First law of thermodynamics
the total energy in the universe remains constant and thus is said to be conserved. Although energy can change from one form to another, it cannot be created or destroyed.
Second law of thermodynamics
When energy is transformed, there is an increase in entropy or disorder. In every transformation of energy, some energy is lost, but not destroyed, it changes into less usable forms.
Autotrophs
Organisms that produce their own food energy.
