Which of the following is NOT part of Dalton’s atomic theory?

• All elements are composed of atoms.

• Atoms are always in motion.

• Atoms of the same element are identical

• Atoms that combine do so in simple whole-number ratios.

Who was the first person to suggest the idea of atoms, in the 4th century B.C.?

• Atomos

• Dalton

• Democritus

• Galileo

• Aristotle

The nucleus of the atom:

• is positively charged and has a high density.

• is positively charged and has a low density.

• is negatively charged and has a high density.

• is negatively charged and has a low density.

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NGSS.HS-PS1-8

The number of neutrons in the nucleus can be calculated by:

• adding together the number of electrons and protons.

• subtracting the number of electrons from the number of protons.

• subtracting the number of protons from the mass number.

• adding the mass number to the number of electrons.

Isotopes of the same element have different:

• numbers of neutrons

• numbers of protons

• numbers of electrons

• atomic numbers

The number 84 in the name krypton-84 represents

• the atomic number

• the mass number

• The sum of the protons and electrons

• none of these

Who discovered the nucleus?

• Rutherford

• Chadwick

• Thomson

• Dalton

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NGSS.HS-PS1-8

Using the periodic table, determine the number of neutrons in uranium-238.

• 92

• 238

• 146

• 235

• 155

Which set of quantum numbers is correct for an electron in a 3d sublevel?

• 3,3,0,1/2

• 3,2,0,1/2

• 3,1,0,-1/2

• 3,2,3,1/2

Which set of quantum numbers could represent the outermost electron in a Na atom (ground state)?

• 2,0,0,-1/2

• 3,1,0,1/2

• 3,0,0,1/2

• 2,1,0,1/2

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2