Atoms and the Periodic Table — Reading Comprehension

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Grades

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MS-PS1-1

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This passage explores the atomic structure of matter and how it informs the organization of the modern periodic table, as outlined by NGSS standard MS-PS1-1. Students will learn about the importance of atomic number, electron arrangement, and how these features determine the properties and placement of elements. The passage uses real-world connections and examples to deepen understanding, while also addressing how to read element squares for symbol, name, atomic number, and atomic mass. Activities include comprehension questions, writing prompts, vocabulary review, and graphic organizers, all designed to support diverse learners. The resource is audio-integrated and provides English and Spanish versions, making it accessible to a wide range of students. This engaging, standards-aligned lesson helps students connect atomic theory to observable patterns in chemistry and everyday life.

CONTENT PREVIEW

chemical-symbols-4 — Atoms are the basic building blocks of all matter

Atoms are the basic units that make up all matter, from the air we breathe to the devices we use every day. Scientists have discovered that each atom contains even smaller particles—protons, neutrons, and electrons. The way these particles are arranged gives each atom its unique properties. The periodic table is a powerful tool that scientists use to organize and understand the elements based on these atomic structures. By examining atomic structure, we can see patterns that explain why elements behave the way they do and how they interact with each other.

The Structure of Atoms and Their Organization

Every atom has a tiny, dense center called the nucleus, which contains protons (positively charged) and neutrons (no charge). The number of protons in the nucleus is called the atomic number, which is the main way scientists identify different elements. For example, all hydrogen atoms have 1 proton, so hydrogen's atomic number is 1. Surrounding the nucleus are electrons, which are arranged in areas called energy levels or shells. The arrangement of electrons, especially those in the outermost shell, affects how an atom reacts with others. Elements with similar electron arrangements often have similar chemical properties, which is why they are placed in the same group or column on the periodic table.

The Modern Periodic Table and Its Patterns

The periodic table organizes elements in order of increasing atomic number, not by atomic mass as was once done. This arrangement reveals repeating, or periodic, patterns in properties like reactivity and state of matter. Each square on the table provides important information: the element's symbol (like H for hydrogen), its name, atomic number, and atomic mass. For example, the element carbon has a symbol C, atomic number 6, and an atomic mass close to 12.01. The rows of the table are called periods, and the columns are groups. Elements in the same group have similar chemical behavior due to their outer electron arrangement, while properties change gradually across a period.

Connecting Structure, Properties, and Use

Understanding atomic structure helps explain why elements are used in certain ways. For instance, sodium and chlorine are both highly reactive because of their electron arrangements, but when combined, they form table salt—a stable compound. The arrangement of electrons also helps us predict which elements are likely to bond or form compounds. This scientific knowledge is crucial in fields like medicine, technology, and environmental science. For example, knowing how elements interact allows engineers to design safer batteries, doctors to use radioactive elements in medical imaging, and chemists to create materials with new properties. The periodic table continues to be a guide for discovering new elements and predicting their behavior.

In summary, the periodic table is more than just a chart. It reflects deep connections between atomic structure and the properties of matter. By studying these patterns, scientists can understand, predict, and harness the behavior of elements for countless applications in our world.

Interesting Fact:
There are currently 118 confirmed elements on the periodic table, but new elements may still be discovered or created in laboratories!

What is the main purpose of the periodic table?

To organize elements based on their atomic number and properties.To show pictures of all elements.To display the history of chemistry.To list all compounds known to science.

Which particle has a positive charge in the atom?

ProtonNeutronElectronNucleus

What does the atomic number tell you about an atom?

The number of protons in the nucleus.The number of electrons in the outer shell.The mass of the atom.The number of neutrons in the atom.

According to the passage, why are elements in the same group similar?

They have similar arrangements of electrons in their outer shells.They all have the same atomic mass.They are all gases.They are always next to each other in periods.

What is found inside the nucleus of an atom?

Protons and neutronsElectrons and neutronsProtons and electronsOnly electrons

What does the word 'symbol' mean in the context of the periodic table?

A one- or two-letter abbreviation for an element.A sign for mathematical equations.A type of atomic particle.A group of atoms joined together.

What does the passage suggest about the usefulness of the periodic table?

It helps scientists predict how elements behave and how they can be used.It makes atoms bigger.It changes the number of protons in atoms.It shows which elements are the most expensive.

How does electron arrangement affect chemical reactivity, according to the passage?

Atoms with similar outer electron arrangements react in similar ways.Atoms with more neutrons are more reactive.Atoms with larger nuclei always react faster.Atoms with higher atomic mass are always less reactive.

True or False: The periodic table is organized by atomic mass.

TrueFalse

True or False: There are currently 118 confirmed elements on the periodic table.

TrueFalse