Chemical element

High school (ages 12+)
Science & Technology

Name:

Date:

Step 1 · Read the article

Open the article and read it at the level above. Then answer the questions below in your own words.

https://smallwhale.org/articles/chemical-element

Write what each word means, using the article.

Do not copy the article. Write two things you learned, the way you would explain them to a friend.

Answers below are taken from the article’s stored facts, so they match what the student read.

1. What is the defining characteristic?The number of protons (atomic number) uniquely identifies a chemical element
2. How do isotopes differ from each other?Isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons. They behave the same chemically but can have slightly different physical properties.
3. Why did Mendeleev create the periodic table?Mendeleev arranged elements by increasing atomic number and noticed repeating patterns in their properties. This helped scientists predict new elements and understand how elements relate to each other.

Atomic Number: The count of protons in an atom's nucleus, serving as the unique identifier for an element.
Isotopes: Atoms of the same element that differ in the number of neutrons in their nucleus.
Nucleus: The central core of an atom, containing protons and neutrons.