Flashcards
Atoms and Molecules
Cards in this deck (17)
- 1__________ laid the foundation of chemical science by establishing two important laws of chemical combinationAntoine L. Lavoisier
- 2State the law of conservation of mass.Matter can neither be created nor destroyed in a chemical reaction.
- 3State the law of constant proportions.In a chemical substance, the elements are always present in definite proportions by mass.
- 4State the postulates of Dalton's atomic theory.1- All matter is made up of very tiny particles called atoms, which participate in chemical reactions.
2- Atoms are indivisible particles, which can neither be created nor destroyed in a chemical reaction.
3- Atoms of the same element have identical masses and chemical properties.
4- Atoms of different elements have different masses and chemical properties.
5- Atoms combine in the ratio of small whole numbers to form compounds.
6- The relative number and kinds of atoms are constant in a given compound. - 5Who suggested that the symbols of elements be made from one or two letters of the name of the element?Berzilius
- 6Full form of IUPACInternational Union of Pure and Applied Chemistry- an international scientific organisation which approves names of elements, symbols and units
- 7Define one atomic mass unit.One atomic mass unit is a mass unit equal to exactly one-twelfth the mass of one atom of carbon-12.
- 8Define relative atomic mass of an atom.It is defined as the average mass of the atom of an element, as compared to one-twelfth the mass of one carbon-12 atom.
- 9Define molecule.A molecule is defined as the smallest particle of an element or compound that is capable of an independent existence and shows all the properties of that substance.
- 10Define atomicity.The number of atoms constituting a molecule is known as its atomicity.
- 11What are polyatomic ions?A group of ions carrying a charge is known as a polyatomic ion.
- 12__________ of a compound is a symbolic representation of its composition.Chemical formula
- 13Compounds made of two different elementsBinary compounds
- 14Define molecular mass.The molecular mass of a substance is the sum of the atomic masses of all the atoms in a molecule of the substance. SI unit- u
- 15Define formula unit mass.The formula unit mass of a substance is the sum of all the atomic masses of all atoms in a formula unit of a compound. Si unit=u
- 16Define one mole.One mole of any species is that quantity in number having a mass equal to its atomic or molecular mass in grams.
- 17Define molar mass.It is the mass of one mole of a substance, calculated by taking the numerical value of its atomic/molecular/formula unit mass and changing the units from 'u' to 'g'.
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- Chemistry Flashcards on Atoms and Molecules, created by Mythili Seshu on 13/02/2020.
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- Mythili Seshu
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