The Nucleus

What does the atomic number of an element represent?

• The number of neutrons in the nucleus

• The number of protons in the nucleus

• The total number of electrons and protons

• The average atomic mass

Which scientist's work validated the atomic theory through the study of Brownian motion?

• Marie Curie

• Isaac Newton

• Albert Einstein

• Niels Bohr

Why are isotopes of the same element chemically similar?

• They have the same number of protons

• They have different atomic numbers

• They have the same number of neutrons

• They have the same atomic mass

What role do neutrons play in the nucleus of an atom?

• They are responsible for the atomic number

• They stabilize the nucleus by spacing out protons

• They determine the chemical properties of the element

• They cause the nucleus to be unstable

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How does chemistry serve as a bridge between physics and biology?

• By ignoring the laws of physics

• By studying only living organisms

• By connecting subatomic particles with living systems

• By focusing solely on chemical reactions

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What is the significance of proper notation and symbolism in chemistry?

• It helps in memorizing the periodic table

• It provides a complete identity for each isotope

• It is only used in advanced chemistry

• It simplifies chemical equations

Why can't elements change into others through chemical reactions?

• Because they have a fixed number of protons

• Because they have a fixed number of electrons

• Because they have a fixed atomic mass

• Because they have a fixed number of neutrons

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What is the primary role of electrons in an atom?

• To govern chemical bonding and reactions

• To stabilize the nucleus

• To define the element's identity

• To determine the atomic mass

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How does the concept of isotopes explain the non-whole number atomic masses?

• Isotopes have the same atomic mass

• Isotopes have different chemical properties

• Isotopes have different numbers of protons

• Isotopes have varying natural abundances

What does the study of atomic theory teach about the scientific method?

• It emphasizes the role of experimental evidence and mathematical rigor

• It shows that hypotheses are always correct

• It proves that scientific concepts never change

• It suggests that theories do not need validation