How to Read the Periodic Table

Summary

The periodic table is an organized chart of elements, increasing in atomic mass from top left to bottom right. Each element has a unique atomic number corresponding to its proton count, like hydrogen with one. Elements are grouped by shared properties and color-coded for easy identification. Rows, or periods, indicate the same number of orbitals, and elements are detailed with symbols, atomic numbers, and weights, which help calculate the number of neutrons by subtracting protons from the nearest whole number of the atomic weight.

Takeaways

• 🧩 The periodic table organizes elements by increasing atomic mass from top left to bottom right.
• 🔢 Each element's atomic number corresponds to the number of protons in its atom, like hydrogen with one proton.
• 👨‍👧‍👦 Elements are grouped into families with similar properties, arranged in columns.
• 🎨 Color coding helps to distinguish between metals, semi-metals, and non-metals.
• 📚 Reading rows (periods) from left to right shows elements with the same number of atomic orbitals.
• 🚫 Gaps exist where elements don't fit neatly into groups with similar characteristics.
• 🌌 The rare earth elements, with similar properties, are given a separate section at the bottom.
• 🔤 Each element has a 1-3 letter symbol, like 'O' for oxygen and 'Pb' for lead, derived from their names.
• 📈 The atomic number is displayed at the top of each element's square on the table.
• ⚖️ The atomic weight, including protons and neutrons, is shown and can be used to calculate the number of neutrons.
• 🔄 To find the number of neutrons, round the atomic weight to the nearest whole number for the mass number, then subtract the number of protons.

Q & A

What happens as you move across the periodic table from top left to bottom right?

As you move across the periodic table from top left to bottom right, the number of protons and the atomic mass of each element increases.

What does the atomic number of an element represent?

The atomic number represents the number of protons in one atom of the element.

Why is hydrogen's atomic number 1?

Hydrogen's atomic number is 1 because a hydrogen atom has only one proton.

What is the atomic number of the synthetic element oganesson?

The atomic number of oganesson is 118, meaning it has 118 protons.

How are elements organized into groups or families on the periodic table?

Elements are organized into groups or families in columns, with each group sharing similar physical and chemical properties.

What do the rows across the periodic table represent?

The rows across the periodic table, known as periods, represent elements with the same number of atomic orbitals.

What are atomic orbitals?

Atomic orbitals are regions around an atom's nucleus where electrons are most likely to appear.

Why are there gaps in the periodic table, particularly in the top three rows?

There are gaps in the periodic table because some elements don't fit neatly into groups that share similar physical and chemical characteristics.

What is unique about the rare earth elements on the periodic table?

The rare earth elements, which have nearly indistinguishable chemical properties, are separated out into their own space at the bottom of the periodic table.

What information can be found in each square of the periodic table?

Each square contains the element's symbol, atomic number, and atomic weight, which represents the combined weight of the protons and neutrons in the nucleus.

How can you determine the number of neutrons in an atom using the periodic table?

To determine the number of neutrons, round the atomic weight to the nearest whole number, then subtract the number of protons from this mass number.