L3 Flashcards
(21 cards)
In a chemical reaction, no change in mass takes place. The total mass of the products is equal to the total mass of the reactant
Law of conservation of mass
A compound always contains the same constituent elements in a fixed or definite proportion by mass
Law of definite proportions
If two elements A and B combine to form more than one compound, the masses of B that can combine with a given mass of A are in the ratio of small whole numbers
Law of Multiple Proportions
A brilliant French Chemist who formulated Law of conservation of mass
Antoine Lavoisier
It is said that mass is neither created nor destroyed in ordinary chemical and physical changes
Must start and end with the same amount
Law of conservation of mass
This Theory states
1.each element is composed of extremely small particles called atoms
2.all atoms of a given element are identical, but the atoms of one element are different from the atoms of all other elements
- Atoms of one element cannot be changed into atoms of a different element by chemical reactions; atoms are neither created nor destroyed in chemical reactions
Daltons Atomic theory
Atoms are dense and solid, with no internal structure or subatomic particles considered
Person involved?
Solid sphere 1803
John Dalton
Atoms are described as uniform. Positively charged spheres with electrons embedded within them, similar to raisins in a pudding
Person Involved?
Plum pudding 1897
JJ Thomson
Atom consists of a small, dense, positively charged nucleus at the center, with electrons orbiting around it. Similar to planets orbiting around the sun
Person involved
Nuclear 1911
Ernest Rutherford
Atom consists of a small, dense, positively charged nucleus at the center, with electrons orbiting around it. Similar to planets orbiting around the sun
Person involved
Nuclear 1911
Ernest Rutherford
Electrons move in quantized, discrete energy levels around the nucleus and emit or absorb energy when transitioning between levels
Planetary 1913
Niels Bohr
Electrons do not have definite orbits, but are described by wave functions that represent probability distributions of their locations
Quantum 1920
Erwin Schrodinger
Atoms are tiny balls that Can’t be broken and are all made of the same material. This theory helps explain how different chemicals mix together and what makes them different
Solid sphere model
Who discovered electrons as distinct particles
J.J Thomson
According to this Theory, atoms are like plum pudding with tiny positive charges scattered throughout a cloud of negative electrons. This Theory helped explain why atoms have a neutral charge overall and why they emit light when they collide with each other
Plum pudding model
New Zealand-born physicist known for his contributions to nuclear physics.
First model to propose a central, massive nucleus
Ernest Rutherford
According to this theory, atoms have a nucleus with a positive charge and most of the mass, surrounded by electrons that orbit like planets. It explains why particles can pass through or bounce off atoms, and is the basis of our current understanding of atomic structure
Nuclear Model
Danish physicist known for his pioneering work in atomic structure
Explained atomic spectra with precision
Niels Bohr
According to this theory, electrons orbit the nucleus of an atom in specific energy levels or shells. This theory helped explain why atoms emit light and why they absorb certain colors of light. It also helped explain the stability of atoms and why they don’t fall apart
Planetary model
Austrian physicist renowned for his contributions to quantum mechanics
(Understanding electron behavior)
Erwin Schrodinger
According to this theory, electrons exist as a probable wave like pattern around the nucleus, not in a specific orbit. It explains why electrons act like particles and waves, and is the foundation of our understanding of atomic structure and widely used in modern physics
Quantum model
