ថ្នាក់ទី១០ មេរៀនទី១

The philosopher who stated that all matter is composed of four elements is: Water, Earth, Fire, and Air. Name...

• Dalton

• Aristotle

• Niels Bohr

• Rutherford

Does Aristotle believe in atoms?

• Yes

• No

• Partially

• No answer

How many points does Dalton's atomic theory have?

• 3

• 4

• 5

• 6

In a chemical reaction, the total mass of the reactants equals the total mass of the products. This is known as the law of...

• Conservation of Mass

• Constant Composition

• Multiple Proportions

• Atoms

In a chemical reaction, no atoms are lost or created; atoms are conserved. This is a statement of the law of...

• Conservation of Mass

• Constant Composition

• Multiple Proportions

• Conservation of Atoms

All pure substances have a definite composition and are stable. This is known as the law of...

• Conservation of Mass

• Constant Composition

• Multiple Proportions

• Conservation of Atoms

When two elements combine to form two or more compounds, the mass ratio of the second element to the first is a small whole number. This is known as the law of...

• Conservation of Mass

• Constant Composition

• Multiple Proportions

• Conservation of Atoms

The mass ratio of atoms between element C and element O in the molecule carbon dioxide (CO2) is equal to...

• 1:1

• 1:2

• 2:1

• 2:2

The mass ratio of atoms between element H and element O in the molecule water (H2O) is equal to...

• 1:9

• 1:8

• 8:1

• 9:1

The mass ratio of two elements in a compound is equal to 1:3 or 3:1. What is the compound?

• NH3

• NaCl

• CO2

• CH4