Question

Refer to the periodic table and find the atomic number for each of the following: (a) helium (b) carbon (c) potassium (d) copper (e) selenium (f) silver (g) lead (h) radon

Short answer

Helium: 2, Carbon: 6, Potassium: 19, Copper: 29, Selenium: 34, Silver: 47, Lead: 82, Radon: 86.

Step-by-step solution

Understanding the Atomic Number

The atomic number of an element is the number of protons in the nucleus of an atom of that element. This number is unique to each element and helps to locate it on the periodic table.

Finding Atomic Number of Helium

Locate helium on the periodic table. Helium is found in Group 18 and Period 1. Its atomic number is 2.

Finding Atomic Number of Carbon

Locate carbon on the periodic table. Carbon is found in Group 14 and Period 2. Its atomic number is 6.

Finding Atomic Number of Potassium

Locate potassium on the periodic table. Potassium is found in Group 1 and Period 4. Its atomic number is 19.

Finding Atomic Number of Copper

Locate copper on the periodic table. Copper is found in Group 11 and Period 4. Its atomic number is 29.

Finding Atomic Number of Selenium

Locate selenium on the periodic table. Selenium is found in Group 16 and Period 4. Its atomic number is 34.

Finding Atomic Number of Silver

Locate silver on the periodic table. Silver is found in Group 11 and Period 5. Its atomic number is 47.

Finding Atomic Number of Lead

Locate lead on the periodic table. Lead is found in Group 14 and Period 6. Its atomic number is 82.

Finding Atomic Number of Radon

Locate radon on the periodic table. Radon is found in Group 18 and Period 6. Its atomic number is 86.

Key concepts

The Periodic Table

The periodic table is an organized arrangement of all known chemical elements. It's like a map that scientists can use to understand which elements share similar properties. This table is organized by increasing atomic number, that is, the number of protons in an atom's nucleus. This means you can find helium, carbon, potassium, copper, selenium, silver, lead, and radon simply by knowing their atomic numbers.

• Helium has an atomic number of 2
• Carbon is at 6
• Potassium is 19
• Copper is 29
• Selenium is 34
• Silver is 47
• Lead is 82
• Radon is 86

Besides being arranged by atomic number, the periodic table groups elements by shared chemical properties, making it a very handy resource for predicting the behavior of different substances. Colors and symbols can also be used to help differentiate between different types of elements, such as metals, nonmetals, and metalloids.

Elements

Elements are the building blocks of everything in the universe. If you've ever wondered about what everything is made, elements are the answer. When we're talking about elements, we mean substances that consist of just one type of atom.
Imagine each element having its own unique personality, determined by the number of protons in its nucleus. This number is the atomic number and it's what determines the element’s place on the periodic table.

Elements can bond together in countless ways, forming the vast variety of molecules and compounds that make up the world around us. Helium ( He ), carbon ( C ), potassium ( K ), copper ( Cu ), selenium ( Se ), silver ( Ag ), lead ( Pb ), and radon ( Rn ) are just a few examples of the elements that scientists explore to understand matter and its transformation.

Groups and Periods

Understanding the organization of the periodic table is made simpler by knowing about groups and periods. Each row in the table is called a period, while each column is a group. Periods are like chapters in a book, and they tell us about the number of electron shells an atom of an element has. As you move from left to right across a period, the atomic number increases, indicating more protons and typically more electrons.

Groups, on the other hand, are incredibly helpful because elements in the same group often exhibit similar chemical behaviors due to having the same number of electrons in their outer shell. This is why elements in Group 1, like potassium, and Group 18, like helium and radon, have distinct patterns and functions.

• Group 1 elements are known as alkali metals, which are highly reactive
• Group 18 elements are noble gases that usually do not react easily

Knowing about groups and periods can greatly benefit your understanding of chemistry and the predictable manner in which elements behave.