Chemistry Review Lessons 5, 6 and 7

Review Lesson 5: Elements of the Periodic Table

The periodic table is a systematic arrangement of chemical elements based on their atomic number, which represents the number of protons in an atom's nucleus. This organization allows elements with similar properties to be grouped together, making it a valuable tool for understanding and predicting chemical behavior.

Review Lesson 5: Elements of the Periodic Table

Groups (Families):

The periodic table is divided into vertical columns called groups or families.

Elements within the same group have similar chemical properties because they have the same number of valence electrons, which are the electrons in the outermost energy level of an atom.

There are 18 groups in the modern periodic table, each designated by a number (Group 1 to Group 18) or a specific name (e.g., Group 1 is known as the alkali metals, Group 17 is the halogens, and Group 18 is the noble gases).

Review Lesson 5: Elements of the Periodic Table

Periods:

The periodic table is arranged horizontally into rows called periods.

Elements within the same period do not have similar properties; instead, they exhibit a gradual change in properties from left to right.

There are 7 periods in the modern periodic table, labeled from Period 1 to Period 7.

Review Lesson 5: Elements of the Periodic Table

Element Information:

Each element on the periodic table is represented by a unique symbol (usually one or two letters) and its atomic number.

Elements are arranged in order of increasing atomic number, so as you move from left to right across a period, the atomic number increases by one with each element.

Multiple Choice

What is a group in the periodic table?

• The periodic table is divided into vertical columns called groups or families.

  Elements within the same group have similar chemical properties

  There are 18 groups in the modern periodic table

• Transition metals, found in the d-block, often form colorful compounds and have variable oxidation states.

  Noble gases in Group 18 are characterized by their stability and reluctance to form chemical bonds.

• Each element on the periodic table is represented by a unique symbol (usually one or two letters) and its atomic number.

  Elements are arranged in order of increasing atomic number, so as you move from left to right across a period, the atomic number increases by one with each element.

Open Ended

What are the p in the periodic table?

Poll

What are the periods in the periodic table?

(Select all that apply)

• Each element on the periodic table is represented by a unique symbol (usually one or two letters) and its atomic number.

• Elements are arranged in order of increasing atomic number, so as you move from left to right across a period, the atomic number increases by one with each element.

• There are 18 groups in the modern periodic table, each designated by a number (Group 1 to Group 18) or a specific name (e.g., Group 1 is known as the alkali metals, Group 17 is the halogens, and Group 18 is the noble gases).

• There are 7 periods in the modern periodic table, labeled from Period 1 to Period 7.

The scientific method is a systematic approach used by scientists to investigate and understand natural phenomena. It consists of a series of steps designed to gather empirical evidence and draw reliable conclusions.

Definition

Review Lesson 6: The Scientific Method

Observation:

The scientific process begins with making observations about the natural world. These observations can be qualitative (descriptive) or quantitative (involving measurements).

Question:

Based on the observations, a specific question or problem is formulated. This question should be clear, focused, and testable.

Hypothesis:

A hypothesis is a tentative explanation or prediction that can be tested through experimentation or further observations. It should be based on existing knowledge and be falsifiable, meaning it can be proven false if the evidence contradicts it.

Steps of the Scientific Method

Review Lesson 6: The Scientific Method

Experimentation and Data Collection:

Controlled experiments are designed to test the hypothesis. This involves manipulating one or more variables while keeping other factors constant (controls).

Data is collected during the experiment, often in the form of measurements, observations, or data points.

Analysis:

The collected data is analyzed to identify patterns, trends, or relationships. Statistical methods may be used to determine the significance of the results.

Conclusion:

Based on the analysis of the data, a conclusion is drawn. This conclusion should address the original question and be supported by the evidence collected during the experiment.

Steps of the Scientific Method

Review Lesson 6: The Scientific Method

When formulating a hypothesis using the "if... then... because..." structure, you are essentially proposing a cause-and-effect relationship between two variables.

If: This part of the hypothesis represents the independent variable, which is the factor you are manipulating or studying to observe its effect. It's the "cause" in the cause-and-effect relationship you're proposing. The "if" portion sets the stage by describing the condition or situation you're interested in.
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Then: This part of the hypothesis represents the dependent variable, which is the outcome or result you expect to observe due to the changes you made to the independent variable. It's the "effect" in the cause-and-effect relationship. The "then" portion outlines the expected consequence of the manipulation of the independent variable.
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Because: This part of the hypothesis provides the rationale or explanation for why you believe the proposed cause-and-effect relationship exists. It includes the scientific reasoning or background information that supports your hypothesis. It's important because it demonstrates your understanding of the underlying principles and mechanisms involved.

The Hypothesis in the Scientific Method

Review Lesson 6: The Scientific Method

Multiple Choice

What is the scientific method?

• The scientific method is a systematic approach used by scientists to investigate and understand natural conclusions.

• The scientific method uses observable data to create theories about phenomenon.

• The scientifis method applies empirical knowledge to design experiments without any hypothesis.

Open Ended

Explain briefly the steps of the sceintific method

Open Ended

Write an example of a hypothesis with the structure if..then...because

Review:Lesson 7
Units of Measurement

Multiple Choice

The function of the International System of Measure Organization is

• To standardize and regulate the units of measure used around the world.

• To explain the use of ft, in and lb as units of measure.

• To stablish new units of measurement every year and publish them at the beginning of each cycle

• All other options are correct

Open Ended

Explain the nature of the conversion factor and its general formula

Complete exercises of Lesson 8, First Worksheet.

“The more you practice, the better you get, the more freedom you have to create.” – Jocko Willink