Atomic Models and Electronic Configuration

Which particles in an atom have a positive charge?

What is the electronic configuration of magnesium?

How does the valency of hydrogen affect the molecular formula of water?

Which of the following statements best describes atomic mass number?

What is the neutron number in the isotope 23Na11?

What is the main difference between Thomson's and Rutherford's models of the atom?

What does valency represent in an element?

How is the atomic mass number defined?

Which of the following statements about neutrons is true?

Why are atoms considered electrically neutral?

Which of the following best describes isotopes?

Why is the atomic mass number always a whole number?

What defines a proton's characteristics?

What role does a moderator play in nuclear reactors?

Atomic Models

Thomson's model proposed a positively charged sphere with electrons embedded, while Rutherford's model proposed a dense, positively charged nucleus with orbiting electrons.
Valency refers to an element's combining capacity, determined by the number of valence electrons.
Atomic mass number is the total number of protons and neutrons in an atom.
Subatomic particles are smaller than atoms.
- Protons are positively charged, have a relatively large mass, and are located in the nucleus.
- Neutrons are neutral, have a large mass, and reside in the nucleus.
- Electrons are negatively charged, have a tiny mass, and exist in orbitals around the nucleus.

Electronic Configuration and Valency

Electron shells are energy levels within an atom where electrons reside.
Magnesium (atomic number 12) has an electronic configuration of 2, 8, 2. The outermost shell (valence shell) has 2 electrons, determining its valency.
Water's molecular formula (H₂O) indicates hydrogen's valency of 1, while iron oxide (Fe₂O₃) implies iron's valency of 3.

Matching Pairs

Proton - Positively Charged
Electron - Negatively Charged
Neutron - Neutral

Deduce from Datum

The number of neutrons in 23Na11 is 12, the mass number is 23, and the proton number is 11.
For 14C6, the mass number is 14, and the proton number is 6.
37Cl17 indicates a proton number of 17 and an atomic number of 17.

Additional Notes

The text mentions the first nuclear reactor in India to be built, indicating its importance in nuclear technology development.
The concepts of atomic number, mass number, and isotopes are highlighted throughout the notes.

Explore the fundamentals of atomic models and electronic configuration in this quiz. Learn about Thomson's and Rutherford's theories, the concept of valency, and the arrangement of electrons in atoms. Test your knowledge on subatomic particles and their roles in chemical behavior.