STAAR 8 Atoms and Periodic Table

Which statement accurately describes the atoms of a specific element?

• A nickel, Ni, atom contains 32 electrons outside the nucleus and 64 neutrons inside the nucleus.

• A tellurium, Te, atom contains 52 protons inside the nucleus and 26 electrons outside the nucleus.

• A calcium, Ca, atom contains 20 protons inside the nucleus and 20 electrons outside the nucleus.

• A bromine, Br, atom contains 35 protons outside the nucleus and 35 electrons inside the nucleus.

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Which statement correctly describes the location and charge of neutrons in an atom?

• The neutrons are inside the nucleus and have a negative charge.

• The neutrons are outside the nucleus and have a neutral charge.

• The neutrons are inside the nucleus and have a neutral charge.

• The neutrons are outside the nucleus and have a negative charge.

What is the difference in the number of electrons in an atom of silicon (Si) and an atom of iodine (I)?

• 67

• 39

• 98

• 98.815

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How many protons, neutrons, and electrons are present in an atom of Barium (Ba) with a mass number of 138?

• 56 protons, 82 neutrons, and 56 electrons

• 56 protons, 138 neutrons, 82 electrons

• 56 protons, 81 neutrons, and 56 electrons

• 56 protons, 56 neutrons, and 56 electrons

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An atom of a certain element has 14 protons, 14 electrons, and a mass number of 27. At room temperature it serves as an excellent semiconductor. How many neutrons are in this atom?

• 28

• 14

• 27

• 13

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In the early 1900s many scientists thought that an atom consisted of a positive substance with negative charges scattered throughout the substance. Then Ernst Rutherford completed an experiment that changed our understanding of atomic structure. Now we know that an atom consists mostly of empty space with ---

• protons orbiting a dense nucleus of electron and neutrons

• electrons orbiting a dense nucleus of protons and neutrons

• neutrons and protons orbiting a cloud of electrons

• electrons and protons orbiting a cloud of neutrons

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What is the mass number of a carbon (C) atom that has 8 neutrons?

• 12

• 12.011

• 14

• 14.011

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Which of these best describes a neutron?

• It has no charge and about the same mass as a proton

• It has a negative charge and about the same mass as a proton

• It has no charge and about the same mass as an electron

• It has a negative charge and about the same mass as an electron

An atom has 82 protons, 125 neutrons, and 82 electrons. What is the charge of the atom's cloud?

• +82

• -82

• +125

• 0

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Based on these drawings, which element is the least reactive?

• Chlorine (Cl) because it has three energy levels and seven electrons in the third level

• Krypton (Kr) because it has four energy levels and eight electrons in the fourth level

• Zinc (Zn) because it has four energy levels and two electrons in the fourth level

• Sodium (Na) because it has three energy levels and one electron in the third level

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