Physical Science Atomic Structure and the Periodic Table

Mason is studying chemistry and he comes across an element with an atomic number of 23 and an atomic mass of 51. Emma asks him how many electrons are in a neutral atom of this element. What should Mason's answer be?

• 23

• 28

• 51

• 74

Answer explanation

The atomic number of an element represents the number of electrons in a neutral atom. Therefore, Mason's answer should be 23, as it matches the atomic number of the element.

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Liam, Aiden, and Abigail are studying the structure of an atom for their science project. They are debating which subatomic particle within the atom has the least amount of mass. Can you help them?

• electrons

• protons

• neutrons

Answer explanation

Electrons have the least amount of mass compared to protons and neutrons. They are negatively charged particles that orbit around the nucleus of an atom.

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Abigail, Mason, and Isla are studying the periodic table. They notice the number 5 at the top of the square for boron. What does this number tell them about boron?

• Boron has 5 isotopes.

• A boron nucleus has 5 protons.

• Boron has an average atomic mass of 5.

• A boron atom has 5 electrons in its outermost energy level.

Answer explanation

The number at the top of the square for boron indicates that a boron nucleus has 5 protons.

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Abigail, Mason, and Daniel are studying the periodic table. They notice that the atomic mass of Boron is rounded to 11. What does this tell them about Boron?

• Boron has 11 isotopes.

• A boron nucleus has 11 protons.

• Boron's most common isotope (form) has an atomic mass of 11.

• A boron atom has 11 electrons in its outermost energy level.

Answer explanation

The atomic mass of Boron being rounded to 11 indicates that Boron's most common isotope has an atomic mass of 11.

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Abigail, Olivia, and Zoe are studying chemistry together. They learn that the horizontal row on the periodic table is called a(n)

• family and the elements all have the same number of valence electrons.

• family and the elements all have the same number of energy levels.

• period and the elements all have the same number of energy levels.

• period and the elements all have the same number of valence electrons.

Answer explanation

The horizontal row on the periodic table is called a period and the elements all have the same number of energy levels.

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Aiden, Oliver, and Noah are studying chemistry together. They are discussing the periodic table and Aiden asks, 'What do we call the vertical column of elements on the periodic table?'

• It's called a family and all the elements in it have the same number of valence electrons.

• It's called a family and all the elements in it have the same number of energy levels.

• It's called a period and all the elements in it have the same number of energy levels.

• It's called a period and all the elements in it have the same number of valence electrons.

Answer explanation

The vertical column of elements on the periodic table is called a family or group and all the elements in it have the same number of valance electrons.

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During a science class, Lily, Samuel, and Evelyn were discussing the periodic table. Samuel pointed out the zigzag line on the right side of the periodic table and asked, 'What is the purpose of this zigzag line?'

• It divides the metals and nonmetals and shows where the metalloids are.

• It indicates a group of elements that have the same chemical properties.

• It connects the elements in the table that have the same atomic number.

• It marks the border between the alkali metals and the transition metals.

Answer explanation

The zigzag line on the periodic table divides metals and nonmetals, indicating the location of metalloids.

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Kai, Jackson, and Avery are in a science class learning about elements. Their teacher asks them, 'Which element in family 17 has the greatest atomic mass?'

• F

• Cl

• Br

• I

Answer explanation

The element with the greatest atomic mass in family 17 is Iodine (I).

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Label the atom model.

a

b

c

d

e

Nucleus

Electron

Proton

Energy Level

Neutron

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James, Evelyn, and Grace are studying chemistry. They come across an atom of chlorine with 17 protons, 17 electrons, and 18 neutrons. They start debating about its atomic mass. James thinks it's about

• 35 AMU

• 34 AMU

• 18 AMU

• 17 AMU

Answer explanation

The atomic mass of an atom is determined by the sum of protons and neutrons. In this case, chlorine has 17 protons and 18 neutrons, resulting in an atomic mass of 35 AMU. Therefore, the correct choice is 35 AMU.

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