AS - Atomic Structure

In which species are the number of electrons and neutrons equal?

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The radioactive isotope of Thallium - 201, is used to assess damage in the heart muscles after a heart attack.

Which statement about Thallium - 201 is correct?

• The isotope has a nucleon number of 120

• The number of electrons in one atom of this isotope is 81

• The number of neutrons in one atom of this isotope is 201

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John Dalton's atomic theory, published in 1808, contained four predictions about atoms. Which of his predictions is still considered to be correct.

• Atoms are very small in size

• No atom can be split into simpler parts

• All the atoms of a particular element have the same mass

• All the atoms of one element are different in mass from all the atoms of other elements

The diagrams show the possible paths of subatomic particles moving through an electric field in a vacuum. Which diagrams are correct?

• 1 and 2 only

• 1 and 3 only

• 2 and 3 only

• 1, 2 and 3

Skin cancer can be treated using a radioactive isotope of phosphorus. A compound containing the phosphide ion ³²P^3- wrapped in a plastic sheet, is strapped to the affected area. What is the composition of the phosphide ion. ³²P^3-?

• 15p, 17n, 18e

• 15p, 17n, 32e

• 17p, 15n, 17e

• 32p, 17n, 15e

In which species are the numbers of protons, neutrons, and electrons all different?

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Value representing the number of protons in an element

• Atomic Mass
• Mass Number
• Valence Electrons
• Atomic Number

A charged atom

• Ion
• Isotope
• Electron Cloud
• Quark

What is one way Neutrons are different from electrons?

• they both are negative

• neutrons have no charge, while electrons have a negative charge

• Both are in the nucleus( center of atom)

• Electrons are inside nucleus and neutrons are outside the nucleus.

The __________ of an atom is the sum of the protons and neutrons in the nucleus of that atom.

• mass number

• atomic number

• ionic charge

• isotope weight