Full Answer Section

The number of neutrons in an atom’s nucleus can vary. Atoms of the same element with different numbers of neutrons are called isotopes.

The electrons in an atom orbit the nucleus in shells. Each shell can hold a certain number of electrons. The first shell can hold up to 2 electrons, the second shell can hold up to 8 electrons, and so on.

The electrons in the outermost shell are called valence electrons. These electrons are responsible for the chemical properties of the atom.

Interpret the Periodic Table of Elements.

The periodic table is a chart that organizes all of the elements known to science. The elements are arranged in order of increasing atomic number.

The periodic table can be used to understand the properties of the elements. For example, elements in the same column of the periodic table have similar chemical properties.

The periodic table can also be used to predict the behavior of elements. For example, elements that are close to each other on the periodic table are likely to react with each other in similar ways.

Analyze the principles of chemical reactions.

A chemical reaction is a process in which one or more substances are transformed into one or more new substances. Chemical reactions are governed by the laws of conservation of mass and energy.

The law of conservation of mass states that mass cannot be created or destroyed in a chemical reaction. The law of conservation of energy states that energy cannot be created or destroyed in a chemical reaction, but it can be converted from one form to another.

There are four types of chemical reactions:

• Combination reactions: Two or more substances combine to form a new substance.
• Decomposition reactions: A single substance breaks down into two or more substances.
• Single-replacement reactions: One element replaces another element in a compound.
• Double-replacement reactions: Two compounds exchange elements.

Apply the scientific method to experimental data.

The scientific method is a systematic way of gathering and interpreting information. It is used to answer questions about the natural world.

The scientific method consists of the following steps:

1. Observe: Make observations about the natural world.
2. Form a hypothesis: Develop a possible explanation for your observations.
3. Test the hypothesis: Conduct experiments to test your hypothesis.
4. Analyze the data: Collect and interpret data from your experiments.
5. Draw conclusions: Make conclusions about your hypothesis based on your data.
6. Communicate your findings: Share your findings with others.

Apply principles of measurement.

Measurement is the process of assigning numbers to physical quantities. There are two main types of measurement:

• Direct measurement: The quantity is measured directly using a measuring instrument.
• Indirect measurement: The quantity is measured indirectly by measuring other quantities that are related to it.

When measuring, it is important to be accurate and precise. Accuracy refers to how close the measured value is to the true value. Precision refers to how reproducible the measured value is.

There are a number of different units used for measurement. The most common units are the metric units. The metric system is based on the meter, kilogram, and second.