Question

HI CAN SOMEONE HELP ME WITH THIS 2 QUESHTIONS PLEASE ITS URGENTLY I DONT UNDER STAND THEM.!!!!!!! my school school closed and I need help rapidly

1.The discovery of the electron contradicted which statement in DaltonÕs atomic theory?

A. All matter consists of small indivisible particles called atoms.

B. Atoms of different elements have different masses.

C. Chemical reactions involve the rearrangement of atoms.

D. Atoms are neither created nor destroyed in chemical reactions.

2.Compared to the properties of their constituent elements, the properties of chemical compounds are generally:

A. Group of answer choices

B. similar to those of the elements.

C. different from those of the elements.

D. similar or different, depending on the substances.

Answer 1

1. The first postulate of Dalton's atomic theory is that all matter consists of small indivisible particles called atoms. This means an atom is indivisible but we now know that an atom consists of protons and neutrons in nucleus and electrons moving around the nucleus. Thus the discovery of electron contradicted the given postulate that an atom is indivisible. So the correct answer is option A.

Option B is incorrect as this related to masses of atoms and mass of electron is negligible.

Option C is incorrect as it has nothing to do with discovery of electrons but rearrangement of atoms during a chemical reaction.

Option D is incorrect as it has nothing to do with discovery of electrons but the obeying of law of conservation of matter during a chemical reaction.

2. A chemical compound has atoms of two or more elements combined in a fixed proportion by mass. It has properties different from that of its constituent elements. For example, compound FeS is made from elements Fe and S. Fe (iron) can be attracted by magnet but FeS is not attracted by magnet.

So statement C is correct. Option B is incorrect as properties of a compound are not the same as that of its constituent elements. So option A. and D. are also incorrect.