CRASHCOURSE QUIZ BLOCK 5

An atom consists of a positively charged nucleus and negatively charged electrons in orbit around the nucleus. Which of the following best describes this structure?

• A positively charged nucleus with negatively charged electrons orbiting it.

• A negatively charged nucleus with positively charged electrons orbiting it.

• A neutral nucleus with neutral electrons orbiting it.

• A positively charged nucleus with neutral electrons orbiting it.

Know how atoms may form positive ions by losing electrons or form negative ions by gaining electrons.

• Atoms may form positive ions by losing electrons or form negative ions by gaining electrons.

• Atoms may form positive ions by gaining electrons or form negative ions by losing electrons.

• Atoms may form positive ions by sharing electrons or form negative ions by splitting electrons.

• Atoms may form positive ions by splitting electrons or form negative ions by sharing electrons.

The scattering of alpha (α) particles by a thin metal sheet provides evidence for which of the following features of the nuclear model of the atom?

• A very small, positively charged nucleus containing most of the atom's mass, surrounded by mostly empty space

• A large, negatively charged nucleus surrounded by dense electrons

• A nucleus made entirely of electrons with no empty space in the atom

• A uniform distribution of mass and charge throughout the atom

The composition of the nucleus in terms of protons and neutrons is:

• It consists of protons and neutrons.

• It consists of electrons and protons.

• It consists of electrons and neutrons.

• It consists of only protons.

State the relative charges of protons, neutrons and electrons as +1, 0 and -1 respectively.

• Proton: +1, Neutron: 0, Electron: -1

• Proton: 0, Neutron: -1, Electron: +1

• Proton: -1, Neutron: +1, Electron: 0

• Proton: +1, Neutron: -1, Electron: 0

The proton number (atomic number) Z is the number of protons in a nucleus, and the nucleon number (mass number) A is the total number of protons and neutrons. The number of neutrons in a nucleus can be calculated by:

• A - Z

• Z - A

• A + Z

• Z / A

Use the nuclide notation.

• ^A_ZX represents a nuclide with mass number A and atomic number Z.

• ^Z_AX represents a nuclide with atomic number A and mass number Z.

• ^A_XZ represents a nuclide with mass number Z and atomic number A.

An isotope is defined as atoms of the same element with different numbers of neutrons, and an element may have more than one isotope. Which of the following best describes an isotope?

• Atoms of the same element with different numbers of neutrons

• Atoms of different elements with the same number of neutrons

• Atoms of the same element with the same number of neutrons

• Atoms of different elements with different numbers of protons

Nuclear fission and nuclear fusion can be described as the splitting or joining of nuclei, including the nuclide equation and qualitative description of mass and energy changes without values. Which statement best summarizes these processes?

• Nuclear fission is the splitting of a heavy nucleus into lighter nuclei, releasing energy, while nuclear fusion is the joining of light nuclei to form a heavier nucleus, also releasing energy, with both involving changes in mass and energy as shown in nuclide equations.

• Nuclear fission and fusion both involve only the joining of nuclei, with no change in mass or energy.

• Nuclear fission is the joining of light nuclei, and nuclear fusion is the splitting of heavy nuclei, both without energy release.

• Both nuclear fission and fusion do not involve any change in nuclei or energy.

Know the relationship between the proton number and the relative charge on a nucleus.

• The proton number determines the relative charge of the nucleus.

• The neutron number determines the relative charge of the nucleus.

• The mass number determines the relative charge of the nucleus.

• The electron number determines the relative charge of the nucleus.