3. atoms and molicules Flashcards
Question: Who was the Indian philosopher that first postulated the idea of the smallest particles of matter?
Maharishi Kanad
Which of the following is a law established by Antoine L. Lavoisier related to chemical reactions?
Law of Conservation of Mass
What name did Maharishi Kanad give to the smallest, indivisible particles of matter?
parmanu
What does the Law of Conservation of Mass state?
Mass can neither be created nor destroyed in a chemical reaction.
Question: Which of the following is NOT a postulate of Dalton’s atomic theory?
A) All atoms of a given element are identical in mass and properties.
B) Atoms cannot be created or destroyed in a chemical reaction.
C) Atoms of different elements can combine in simple whole-number ratios to form compounds.
D) Atoms can be subdivided into protons, neutrons, and electrons.
Atoms can be subdivided into protons, neutrons, and electrons.
Question: Who is credited with the development of the atomic theory that suggested that matter is made up of tiny, indivisible particles called atoms?
John Dalton
Which law states that in a chemical reaction, the total mass of the reactants is equal to the total mass of the products?
Law of Conservation of Mass
What term is used to describe a substance that is made up of two or more different elements chemically combined in a fixed ratio?
Compound
Which of the following particles are found inside the nucleus of an atom?
) Protons and neutrons
What did Democritus and Leucippus call the smallest, indivisible particles of matter?
atom
Which ancient Greek philosopher is known to have suggested the concept of indivisible particles called atoms?
Leucippus
Which scientist laid the foundation of chemical sciences by establishing important laws of chemical combination?
Antoine L. Lavoisier
Which other philosopher, apart from Maharishi Kanad, contributed to the idea of particles existing in a combined form?
Pakudha Katyayama
Which law states that mass can neither be created nor destroyed in a chemical reaction?
Law of Conservation of Mass
Which scientist proposed the ‘plum pudding model’ of the atom?
J.J. Thomson
Jolly jam in pudding
According to the Law of Constant Proportions, the elements in a compound are always present in
Definite proportions by mass
Who proposed the Law of Constant Proportions?
Joseph Proust
In water (H₂O), what is the mass ratio of hydrogen to oxygen?
1:8
Which scientist’s atomic theory explained the laws of chemical combination?
John Dalton
According to Dalton’s atomic theory, atoms of a given element are:
Identical in mass and chemical properties
What is the primary focus of Dalton’s atomic theory?
The nature of matter
What modern techniques allow us to see atoms?
A) Optical microscopes
B) Electron microscopes
C) Scanning tunneling microscopy
D) Both B and C
D) Both B and C
Atomic radius is measured in nanometres.
1/10 ^9 m =
1 m =
1/10 ^9 m = 1 nm
1 m = 10 ^9 nm
From where were the names of many elements originally derived?
The names of the places where they were discovered
What is the symbol for iron derived from?
Its Latin name ferrum
What is the atomic mass unit now referred to as, according to the latest IUPAC recommendations?
u (unified mass)
The atomic mass of which element is defined as equal to the mass of one carbon atom? atom?
Carbon
What is a molecule that consists of two atoms called?
Diatomic
Who proposed the atomic theory that stated that matter is made up of atoms that cannot be created or destroyed?
John Dalton
What does the term “valency” refer to in chemistry?
The ability of an atom to bond with others.
compounds in baking powder
Sodium, Hydrogen, Carbon, and Oxygen
