Science 9 - Matter and Chem - Atomic Theories

What is the main purpose of observations in science?

• a. To develop theories
• b. To make predictions
• c. To gather data and information
• d. To create models

Which of the following is an example of an observation?

• a. The atomic number of carbon is 6
• b. Atoms are composed of protons, neutrons, and electrons
• c. When heated, a metal expands
• d. The Bohr model depicts electrons orbiting the nucleus

What is a theoretical idea in science?

• a. Direct observation
• b. Experimental result
• c. Hypothesis or explanation
• d. Controlled variable

In the discovery of the atom, which model proposed that atoms were indivisible and indestructible?

• a. Dalton's model
• b. Thomson's model
• c. Rutherford's model
• d. Bohr's model

How did J.J. Thomson contribute to the understanding of the atom?

• a. Discovered the electron
• b. Proposed the nuclear model
• c. Identified isotopes
• d. Formulated the atomic theory

What experimental evidence led Rutherford to propose the nuclear model of the atom?

• a. Cathode ray tube experiments
• b. Oil drop experiment
• c. Gold foil experiment
• d. Double-slit experiment

Which model of the atom suggested that electrons move in specific orbits around the nucleus?

• a. Dalton's model
• b. Thomson's model
• c. Rutherford's model
• d. Bohr's model

How do scientists use models to explain observations about atomic structure?

• a. By making predictions
• b. By creating visual representations
• c. By conducting experiments
• d. By measuring quantities

What is the current atomic model that considers the probability of finding electrons in certain regions around the nucleus?

• a. Bohr's model
• b. Thomson's model
• c. Rutherford's model
• d. Quantum mechanical model

Which scientist proposed that electrons do not have definite orbits but exist in electron clouds?

• a. Dalton
• b. Thomson
• c. Rutherford
• d. Schrödinger