Question

which of the following did dalton discuss in his atomic theory?
a isotopes
b ions
c protons
d electrons
e neutrons
f daltons theory did not discuss any of these topics.
question 9
how many of the following statements regarding daltons atomic theory is/are still believed to be true?
i. elements are made of tiny particles called atoms.
ii. all atoms of a given element are identical.
iii. a given compound always has the same relative numbers and types of atoms.
iv. atoms are indestructible.
a 1
b 0
c 2
d 4
e 3

Explanation:

• Statement I: Dalton proposed that elements are made of tiny particles called atoms. This is still a fundamental concept in modern atomic theory.
• Statement II: Dalton thought all atoms of a given element are identical. However, we now know about isotopes (atoms of the same element with different numbers of neutrons), so this is false.
• Statement III: Dalton stated that a given compound always has the same relative numbers and types of atoms. This is in line with the law of definite proportions and is still true.
• Statement IV: Dalton believed atoms are indestructible. But with the discovery of nuclear reactions (e.g., fission and fusion), we know atoms can be broken down under certain conditions, so this is false.

Answer:

C. 2