Podcast
Questions and Answers
Which term best describes the smallest unit of matter that retains the identity of a substance?
Which term best describes the smallest unit of matter that retains the identity of a substance?
What is the overall charge of a neutral atom?
What is the overall charge of a neutral atom?
Which subatomic particle is located in the nucleus and carries a positive charge?
Which subatomic particle is located in the nucleus and carries a positive charge?
Which subatomic particle has the smallest mass and is found orbiting the nucleus?
Which subatomic particle has the smallest mass and is found orbiting the nucleus?
Signup and view all the answers
Which scientist is credited with the discovery of the neutron?
Which scientist is credited with the discovery of the neutron?
Signup and view all the answers
What is the relative mass contribution of electrons to the overall mass of an atom?
What is the relative mass contribution of electrons to the overall mass of an atom?
Signup and view all the answers
What does the term 'atomos', from which the word 'atom' is derived, mean?
What does the term 'atomos', from which the word 'atom' is derived, mean?
Signup and view all the answers
Where is most of the mass of an atom located?
Where is most of the mass of an atom located?
Signup and view all the answers
Which subatomic particle has a mass closest to $1.67 \times 10^{-24}$ grams?
Which subatomic particle has a mass closest to $1.67 \times 10^{-24}$ grams?
Signup and view all the answers
According to the provided information, what is the defining characteristic of Democritus's concept of an atom?
According to the provided information, what is the defining characteristic of Democritus's concept of an atom?
Signup and view all the answers
J.J. Thomson's atomic model, often referred to as the 'plum pudding' model, proposed that the atom consists of:
J.J. Thomson's atomic model, often referred to as the 'plum pudding' model, proposed that the atom consists of:
Signup and view all the answers
Which of Dalton's postulates states that atoms of different elements have different masses and properties?
Which of Dalton's postulates states that atoms of different elements have different masses and properties?
Signup and view all the answers
Which of these subatomic particles was the first to be discovered?
Which of these subatomic particles was the first to be discovered?
Signup and view all the answers
Which is NOT a property that Democritus attributed to atoms?
Which is NOT a property that Democritus attributed to atoms?
Signup and view all the answers
What was the primary experimental method used by J.J. Thomson in his discovery of the electron?
What was the primary experimental method used by J.J. Thomson in his discovery of the electron?
Signup and view all the answers
How did Thomson determine that the electron was part of an atom?
How did Thomson determine that the electron was part of an atom?
Signup and view all the answers
According to Schrödinger's atomic model, how do electrons travel around the nucleus?
According to Schrödinger's atomic model, how do electrons travel around the nucleus?
Signup and view all the answers
What determines an element's atomic number?
What determines an element's atomic number?
Signup and view all the answers
If an atom has a mass number of 35 and an atomic number of 17, how many neutrons does it have?
If an atom has a mass number of 35 and an atomic number of 17, how many neutrons does it have?
Signup and view all the answers
What does the atomic notation superscript to the right of the element symbol represent?
What does the atomic notation superscript to the right of the element symbol represent?
Signup and view all the answers
When an atom gains an electron, what type of particle does it become?
When an atom gains an electron, what type of particle does it become?
Signup and view all the answers
What occurs when an electron moves from one energy level to another?
What occurs when an electron moves from one energy level to another?
Signup and view all the answers
What does the left subscript in standard atomic notation denote?
What does the left subscript in standard atomic notation denote?
Signup and view all the answers
If an atom has a charge of zero (0), what can be said about the number of electrons?
If an atom has a charge of zero (0), what can be said about the number of electrons?
Signup and view all the answers
What is the positively charged substance in Thomson's plum pudding model of the atom?
What is the positively charged substance in Thomson's plum pudding model of the atom?
Signup and view all the answers
What did Rutherford's Gold Foil Experiment demonstrate about the atom?
What did Rutherford's Gold Foil Experiment demonstrate about the atom?
Signup and view all the answers
What was a key problem with Rutherford's planetary model of the atom, before Bohr's refinements?
What was a key problem with Rutherford's planetary model of the atom, before Bohr's refinements?
Signup and view all the answers
According to Bohr's model, what determines the energy level of an electron's orbit?
According to Bohr's model, what determines the energy level of an electron's orbit?
Signup and view all the answers
What is contained within the nucleus, according to Rutherford's model?
What is contained within the nucleus, according to Rutherford's model?
Signup and view all the answers
How did Rutherford describe electron movement around the nucleus?
How did Rutherford describe electron movement around the nucleus?
Signup and view all the answers
In the context of Bohr's model, which electrons would occupy the lowest energy level?
In the context of Bohr's model, which electrons would occupy the lowest energy level?
Signup and view all the answers
What is another name for Thomson's atomic model?
What is another name for Thomson's atomic model?
Signup and view all the answers
Study Notes
Atoms
- Atoms are the smallest unit of matter that retains the properties of the substance.
- Atoms are derived from the Greek word "atomos," meaning indivisible.
- All atoms of a particular element are identical in mass and properties.
- Atoms of different elements have different masses and properties.
- Atoms are composed of three subatomic particles: protons, neutrons, and electrons.
Subatomic Particles
- Protons: Positively charged particles located in the nucleus. Discovered by Eugen Goldstein. Ernest Rutherford coined the term.
- Neutrons: Neutral particles located in the nucleus. Discovered by James Chadwick.
- Electrons: Negatively charged particles orbiting the nucleus. Discovered by Joseph John Thomson. Electrons are much lighter than protons and neutrons.
Nucleus
- The nucleus is at the center of the atom.
- Much of the atom's mass is concentrated in the nucleus (approximately 99.9%).
- The nucleus contains protons and neutrons.
Neutral Atoms
- A neutral atom has an equal number of protons and electrons.
- The negative charge of the electrons balances the positive charge of the protons.
- An atom becomes stable when it has a filled valence shell, a configuration defined by energy levels.
Atomic Structure
- The atom's overall shape is spherical.
- The nucleus is very small compared to the overall size of the atom.
- Electrons orbit around the nucleus.
- The space outside the nucleus is mostly empty.
Atomic Number
- The atomic number of an element is the number of protons in its nucleus.
- Each element has a unique atomic number.
- Every atom of a certain element has the same atomic number.
- Example: An atom of hydrogen has 1 proton and an atomic number of 1. An atom of gold has 79 protons and an atomic number of 79.
Mass Number
- The mass number of an atom is the total number of protons and neutrons in its nucleus.
Atomic Mass
- Atomic mass is the average mass of the naturally occurring isotopes of an element.
- It's calculated by considering the mass of each isotope and its abundance.
Atomic Notation
- A shorthand way to represent an element's symbol, atomic number, mass number, and charge.
- For example, an oxygen atom with 8 protons, 8 neutrons, and an overall charge of 0 is represented as $^{16}_8$O.
- Atomic number is shown as a subscript on the left of the element symbol.
- Mass number is shown as a superscript on the left of the element symbol.
- Charge is shown as a superscript on the right of the element symbol.
Ions
- An ion is an atom that has gained or lost electrons.
- Cations have a net positive charge.
- Anions have a net negative charge.
Isotopes
- Isotopes are atoms of the same element with the same atomic number but different mass numbers.
- Isotopes have the same number of protons and electrons, but different numbers of neutrons.
- Isotopes are identified by their mass number (e.g., Carbon-12, Carbon-13, Carbon-14).
Radioactive Decay
- Some isotopes are radioactive, meaning they are unstable and undergo radioactive decay.
- This process is measured by their half life, which represents the time it takes for half of the radioactive atoms to decay.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Test your knowledge on the fundamental concepts of chemistry with this quiz focused on atomic structure. Questions cover topics including subatomic particles, atomic theories, and key scientists in the field. Challenge yourself to understand the building blocks of matter!
