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Chapter 2: Problem 101

The atomic number for an atom containing 20 protons, 21 neutrons, and 20 electrons is

Short Answer

Expert verified
The atomic number is 20.

Step by step solution

01

Identify the number of protons

The atomic number of an element is defined by the number of protons in its nucleus. In the given problem, the atom contains 20 protons.
02

State the atomic number

Since the atomic number is directly equal to the number of protons in the nucleus, and the given atom has 20 protons, the atomic number of this atom is 20.

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

protons
Protons are subatomic particles found in the nucleus of an atom. They carry a positive charge and are counted to determine the atomic number of an element. Each element has a unique number of protons in its nucleus, which distinguishes it from other elements. Similarly charged protons repel each other, but they are held together in the nucleus by a strong force called the nuclear force.
To sum up:
  • Protons are positively charged particles.
  • They are located in the nucleus of an atom.
  • The number of protons determines the atomic number of an element.
atomic structure
Atomic structure refers to the arrangement of subatomic particles in an atom. An atom consists of three main subatomic particles: protons, neutrons, and electrons. Protons and neutrons are located in the nucleus at the center of the atom, while electrons orbit the nucleus in various energy levels or shells. The attractive force between the positively charged protons and negatively charged electrons keeps the electrons in motion around the nucleus.
Key points to remember about atomic structure:
  • Protons and neutrons are in the nucleus.
  • Electrons orbit the nucleus in energy levels.
  • The nucleus contains most of the atom's mass.
element identification
Element identification is the process of determining an element based on its atomic number, which is equal to the number of protons in its nucleus. The periodic table is a useful tool for identifying elements, as it arranges them in order of increasing atomic number. Each element has a unique atomic number and is represented by a chemical symbol. For example, the element with 20 protons (atomic number 20) is calcium, represented by the symbol Ca.
Important points:
  • The atomic number identifies an element.
  • The periodic table helps to find elements based on their atomic numbers.
  • Each element has a unique chemical symbol.

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Most popular questions from this chapter

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