1. Who first proposed the idea of an atom being indivisible?
Answer:
Explanation:
John Dalton introduced the atomic theory in the early 19th century, suggesting that atoms are indivisible and indestructible particles.
2. Which subatomic particle has no charge?
Answer:
Explanation:
Neutrons are neutral particles found in the nucleus of an atom.
3. The Cathode Ray Experiment led to the discovery of:
Answer:
Explanation:
J.J. Thomson's Cathode Ray Experiment in the late 19th century led to the discovery of electrons.
4. What is the charge on a proton?
Answer:
Explanation:
A proton has a positive charge of +1.
5. Who proposed the nuclear model of the atom?
Answer:
Explanation:
Rutherford's gold foil experiment led to the proposal of the nuclear model, where the atom's positive charge and most of its mass reside in the nucleus.
6. The number of protons in an atom is called its:
Answer:
Explanation:
The atomic number represents the number of protons in an atom.
7. Which atomic model proposed the quantization of electron energy levels?
Answer:
Explanation:
Bohr's Model introduced the idea of quantized energy levels for electrons.
8. An ion with more electrons than protons is:
Answer:
Explanation:
If there are more electrons (negative charge) than protons (positive charge), the ion will be negatively charged.
9. Which subatomic particle determines the chemical properties of an atom?
Answer:
Explanation:
Chemical properties of an atom are largely determined by the arrangement and number of its outermost electrons.
10. Isotopes of an element have:
Answer:
Explanation:
Isotopes have the same atomic number (number of protons) but different mass numbers due to varying neutrons.
11. The atomic mass unit (amu) is defined with respect to:
Answer:
Explanation:
The atomic mass unit is defined as one twelfth the mass of a carbon-12 atom.
12. What is the maximum number of electrons that can be accommodated in the n=2 shell?
Answer:
Explanation:
The formula 2n^2 determines the number of electrons. For n=2, it's 2(2^2) = 8.
13. In which orbital would you find electrons with the quantum numbers n=3 and l=2?
Answer:
Explanation:
The azimuthal quantum number l=2 corresponds to the d orbital.
14. Which scientist developed the concept of electron spin?
Answer:
Explanation:
Electron spin was introduced by Paul Dirac.
15. The exclusion principle, which states that no two electrons in an atom can have the same set of quantum numbers, is proposed by:
Answer:
Explanation:
This principle is known as Pauli's Exclusion Principle.
16. What is the shape of an s orbital?
Answer:
Explanation:
s orbitals have a spherical shape.
17. Which atomic model is based on wave mechanics?
Answer:
Explanation:
The Quantum Mechanical Model is based on wave mechanics and the dual nature of matter.
18. Which quantum number describes the orientation of an orbital?
Answer:
Explanation:
The magnetic quantum number describes the orientation of an orbital in space.
19. Who introduced the concept of atomic orbitals?
Answer:
Explanation:
Erwin Schrödinger introduced the concept of atomic orbitals through wave equations.
20. The dual nature of matter and light was proposed by:
Answer:
Explanation:
Louis de Broglie proposed the dual nature of matter and light in his hypothesis.