The model of the atom has changed as scientists have gathered new evidence. Four models of the atom are shown below, but one important model is missing.
I don't understand.... ) :
( A)An atom can join with other kinds of atoms.
(B)Dalton’s model
(D)an atom is made up of electrons in a sea of positive charges.
(A)Bohr’s work with atomic spectra led him to say that the electrons were limited to existing in certain energy levels, like standing on the rungs of a ladder.
Ur welcome!!!!!!!!!!
I approve!!!! : )
The missing model is likely the current model of the atom, known as the electron cloud model or the quantum mechanical model. This model is based on the principles of quantum mechanics, which describe the behavior of particles at the atomic and subatomic level.
To understand how the model of the atom has changed over time, scientists have gathered new evidence through various experiments, including the discovery of subatomic particles such as protons, neutrons, and electrons. These models were proposed to explain the structure of the atom and how its constituents interact.
The four models of the atom that are commonly discussed are:
1. Thomson's Plum Pudding Model: Proposed by J.J. Thomson in the late 19th century, this model suggests that the atom is a uniform positive sphere with negatively charged electrons embedded in it, resembling a "plum pudding" dessert.
2. Rutherford's Nuclear Model: Proposed by Ernest Rutherford in 1911, this model suggests that the atom has a dense, positively charged nucleus at its center, with electrons orbiting around it in empty space. This model was based on the results of the famous gold foil experiment, where Rutherford observed that most of the alpha particles passed through the gold foil, but some were deflected, indicating the presence of a small, dense, and positively charged nucleus.
3. Bohr's Planetary Model: Proposed by Niels Bohr in 1913, this model introduced the concept of energy levels or electron shells. According to this model, electrons exist in specific energy levels around the nucleus, much like planets orbiting the sun. The electrons can jump between energy levels by absorbing or emitting specific amounts of energy.
4. Electron Cloud Model (Quantum Mechanical Model): The missing model in your question, this current model is a result of advancements in quantum mechanics. It suggests that the exact location and velocity of an electron cannot be determined simultaneously, but rather, there is a probability distribution or "cloud" where the electron is likely to be found. This model describes electrons in terms of wave-particle duality, where they can exhibit both particle-like and wave-like behaviors.
To summarize, the model of the atom has evolved from Thomson's Plum Pudding Model to Rutherford's Nuclear Model, then to Bohr's Planetary Model, and finally to the current Electron Cloud Model based on quantum mechanics. Scientists continue to study and refine their understanding of the atom using experimental evidence and theoretical calculations.
I think all four models are missing.
If you google atom or atomic theory I'm sure you will find what you seek.