AP Biology Scientific Method

• The Scientific Method

• ​Atoms and Water

• Properties Carbon Properties

Review Lessons:5, 6 and 7

​The Scientific Method

The scientific method is a systematic approach used by scientists and researchers to investigate and understand natural phenomena, solve problems, and generate reliable knowledge. It is a structured process that helps ensure objectivity, repeatability, and validity in scientific inquiry.

​Steps of the Scientific Method

​
1. Observation: The process begins with the observation of a phenomenon or an interesting question. Observations can be made through direct sensory perception or by reviewing existing literature.

2. Research: After making an observation or formulating a question, scientists gather relevant information and conduct thorough research to better understand the topic. This often involves reviewing existing studies, data, and theories related to the subject.

3. Hypothesis: Based on the information gathered, scientists formulate a hypothesis. A hypothesis is a testable statement or educated guess that proposes a potential explanation for the observed phenomenon. It should be specific, clear, and capable of being tested through experimentation or observation.

​Steps of the Scientific Method

4. Experimentation or Observation: This step involves designing and conducting experiments or making observations to test the hypothesis. Experiments should be carefully planned to manipulate specific variables and collect relevant data. The goal is to gather empirical evidence to support or refute the hypothesis.
5. Data Collection: During experiments or observations, scientists collect data and record measurements. It is crucial to collect data accurately and consistently to ensure the reliability of the results.

6. Analysis: Once data is collected, it is analyzed using statistical and mathematical techniques to determine whether the results support the hypothesis. Scientists look for patterns, trends, and correlations in the data.

7. Conclusion: Based on the analysis of the data, scientists draw conclusions about whether the hypothesis is supported or rejected. These conclusions are not definitive, but they provide insights into the phenomenon under investigation

Writing a Hypothesis

If ... then ... because ....

The "if...then...because" structure is a clear and concise way to formulate a hypothesis in scientific research. It helps researchers articulate their expectations and the rationale behind their study. Here's how the structure works:

If (Independent Variable)

The "if" part of the hypothesis represents the independent variable, which is the factor that the researcher manipulates or examines. This is the variable that you believe may have an effect on the dependent variable.

Then (Expected Outcome)

The "then" part of the hypothesis describes the expected outcome or result of the experiment or observation. It is the effect you anticipate the independent variable will have on the dependent variable.

Because (Rationale or Explanation)

The "because" part of the hypothesis provides the underlying rationale or explanation for why you expect the relationship described in the hypothesis to occur. It explains the scientific basis or reasoning behind your hypothesis.

Multiple Choice

What is the sceintific method?

• The scientific method is a systematic approach used by scientists and researchers to investigate and understand natural phenomena, solve problems, and generate reliable knowledge. It is a structured process that helps ensure objectivity, repeatability, and validity in scientific inquiry.

• There are four common methods of referring to a source document in the text of an essay, thesis or assignment. These methods are direct quotation from another source, paraphasing or summarising material, and citing the whole of a source document.

• If random assignment of participants to control and treatment groups is impossible, unethical, or highly difficult, consider an observational study instead. This minimizes several types of research bias, particularly sampling bias, survivorship bias, and attrition bias as time passes.

Open Ended

Explain the steps of the scientific method

Open Ended

Using the phenomenon of mold growing in bread, write a hypothesis about it, using the structure if...then ... because.

Atoms and Water Properties

​An atom is the basic building block of matter, consisting of a nucleus at its center, composed of protons and neutrons, and a surrounding cloud of electrons. Atoms are the fundamental units of chemical elements, and they combine to form molecules and compounds, which make up all matter in the universe.

Nucleus: The nucleus is the central core of an atom and contains two types of subatomic particles:

Protons: Positively charged particles found in the nucleus. The number of protons in an atom's nucleus determines its atomic number, which defines the element.

Neutrons: Neutrally charged particles (they have no charge) found in the nucleus. Neutrons contribute to the mass of the atom.

Electrons: Electrons are negatively charged particles that orbit the nucleus in specific energy levels or electron shells. Electrons are much lighter than protons and neutrons and are responsible for chemical bonding.

An anion is an ion with a negative electrical charge. It forms when an atom or molecule gains one or more electrons. The addition of electrons creates an excess of negatively charged electrons in relation to positively charged protons, resulting in a net negative charge.

Anions

A cation is an ion with a positive electrical charge. It forms when an atom or molecule loses one or more electrons. The loss of electrons creates an excess of positively charged protons in relation to negatively charged electrons, resulting in a net positive charge.

Cations

Ions: Cations and Anions

Types of Chemical Bonds in Elements

Covalent bonds form when atoms share electrons to achieve a stable electron configuration. Atoms in covalent bonds can share one or more pairs of electrons.

Covalent Bond

Ionic bonds occur when atoms transfer electrons from one to another. In this process, one atom becomes positively charged (cation) because it loses electrons, and the other atom becomes negatively charged (anion) because it gains electrons.

Ionic Bond

Open Ended

Describe the types of covalent bonds?

Multiple Select

The rules for the ionic or covalent bonds among elements is:

(Two correct options)

• The ionic bonds are posible between a metal and a non metal element.

• The covalent bond can be possible between to non metal elements.

• Ionic and covalent cam be formed by any type of element.

• Metallic bond is a cehmical bond between electrons of the metals elements.

Open Ended

Explain the difference between a cation and an anion

​Water and its Properties

What are the properties of water?
High Heat Capacity: Water has a high heat capacity, meaning it can absorb and store a significant amount of heat energy without a large change in temperature. This property helps regulate Earth's temperature and provides stability to aquatic environments.
Density Anomaly: Unlike most substances, water's density decreases as it freezes, causing ice to be less dense than liquid water. This property allows ice to float and insulate bodies of water, protecting aquatic life in cold environments.
Cohesion and Adhesion: Water molecules exhibit cohesion, sticking to other water molecules, and adhesion, sticking to other substances. These properties contribute to capillary action, the ability of water to move against gravity in narrow spaces, such as in plant roots.

Surface Tension: Water has a high surface tension due to the cohesive forces between its molecules. This property allows small organisms like water striders to "walk" on the surface of water and contributes to the formation of droplets.

Universal Solvent for Polar Compounds: Water's polarity enables it to dissolve a wide range of polar substances like salts, sugars, and acids. This property is essential for biological processes, as it facilitates the transport of ions and nutrients in living organisms.
Capillarity, also known as capillary action or capillary rise, is the ability of a liquid, such as water, to flow in narrow spaces against the force of gravity. This phenomenon occurs due to the combined effects of adhesive and cohesive forces acting on the liquid. Capillarity is particularly noticeable in small-diameter tubes, thin channels, or porous materials like soil, paper, and sponges.

Polar and ionic compounds (those with charges) tend to dissolve in water because water is a polar molecule. Nonpolar substances, on the other hand, typically do not dissolve well in water. This rule is a fundamental principle of solubility.

​Solubility in Water

The main cause for the properties of water are the hydrogen bonds, they are weak attractions between a hydrogen atom and a highly electronegative atom (usually nitrogen, oxygen, or fluorine) in another molecule.

This polarization produces another phenomenon, the solubility of polar substances.

Hydrogen Bonds

Hydrogen Bonds & Solubility

Open Ended

Explain four properties of water

Multiple Choice

The cause of the properties of water and the solubility of compounds is

• The covalent boinds

• The ionic bonds

• The hydrogen bonds

• The metallic bonds

Multiple Choice

What waxes are not suluble in water?

• Waxes are ionic compounds soluble in water

• Waxes are non polar compounds, only soluble in non polar solvents

• The hydrogen bonds in waxes make the covalent bonds to attract

• Waxes are exception of solubility, beacuse they are polar compounds

Edpuzzle

You can open this webpage in a new tab.

Copy link

Open in new tab