Questions and Answers
What is the smallest unit of matter?
atom
What is the center of the atom that contains neutrons and protons?
nucleus
What is the outer portion of an atom that contains electrons?
electron cloud
What are neutrally charged subatomic particles located in the nucleus called?
Signup and view all the answers
What are the positively charged subatomic particles located in the nucleus called?
Signup and view all the answers
What is the average mass of all atoms of an element called?
Signup and view all the answers
What is the rounded mass of an atom that includes protons and neutrons?
Signup and view all the answers
What does the atomic number represent?
Signup and view all the answers
What is the form of the Isotope symbol?
Signup and view all the answers
What is text that is reduced in size and lowered to the bottom of the current line?
Signup and view all the answers
What is text that is reduced in size and raised to the top of the current line?
Signup and view all the answers
What do you call the distance of electrons in the electron cloud from the nucleus?
Signup and view all the answers
What are the chemical formula(s) on the left side of the chemical equation called?
Signup and view all the answers
What are the chemical formula(s) on the right side of the chemical equation called?
Signup and view all the answers
What is the law that states mass cannot be created or destroyed?
Signup and view all the answers
What is the number at the beginning of a chemical formula that tells you the number of molecules?
Signup and view all the answers
What are some examples of chemical properties?
Signup and view all the answers
What are examples of physical properties?
Signup and view all the answers
What is a beam of electrons emitted by the cathode of an electrical discharge tube called?
Signup and view all the answers
What does Dalton's Atomic Theory state?
Signup and view all the answers
What are atoms of the same element that have different numbers of neutrons called?
Signup and view all the answers
What is an arrangement of elements in columns based on repeating properties called?
Signup and view all the answers
Who believed that atoms were indivisible and indestructible?
Signup and view all the answers
Who transformed Democritus' ideas about atoms into a scientific theory?
Signup and view all the answers
How can scientists observe individual atoms?
Signup and view all the answers
What are the three types of subatomic particles?
Signup and view all the answers
Which subatomic particles are found in the nucleus of an atom?
Signup and view all the answers
Which subatomic particles are distributed around the edge of the atom?
Signup and view all the answers
Why are elements different?
Signup and view all the answers
Why do isotopes have different mass numbers?
Signup and view all the answers
If an element has an atomic number of 42, what are the numbers of protons and electrons in a neutral atom of that element?
Signup and view all the answers
What does the number 84 in the name krypton-84 represent?
Signup and view all the answers
How many protons, electrons, and neutrons does an atom with atomic number 45 and mass number 92 contain?
Signup and view all the answers
Study Notes
Atomic Structure Overview
- An atom is the smallest unit of matter.
- The nucleus is at the atom's center, housing neutrons and protons, where most of an atom's mass is found.
- The electron cloud surrounds the nucleus and contains electrons, representing most of the atom's volume.
Subatomic Particles
- Neutrons: Neutrally charged, located in the nucleus, with a mass of 1 amu.
- Protons: Positively charged, located in the nucleus, with a mass of 1 amu.
- Electrons: Negatively charged particles that exist in the electron cloud.
Atomic Mass and Structure
- Atomic mass is the average mass of an element's atom.
- Mass number is the sum of protons and neutrons in an atom.
- Atomic number identifies the element based on the number of protons.
Isotopes and Symbols
- Isotopes have the same number of protons but different numbers of neutrons.
- Isotope Symbol consists of mass on top, atomic number on the bottom, and element symbol.
Chemical and Physical Properties
- Chemical properties include reactivity, flammability, and the ability to rust.
- Physical properties include shape, size, texture, and state of matter.
Chemical Equations
- Reactants are the formulas on the left side of a chemical equation.
- Products are the formulas on the right side of a chemical equation.
- The law of conservation of mass states mass cannot be created or destroyed; reactants must equal products.
Fundamental Concepts
- Coefficients indicate the number of molecules in a chemical formula.
- Energy levels refer to the distance of electrons from the nucleus, with the first three levels capable of holding 2, 8, and 8 electrons.
Historical Background
- According to Dalton's Atomic Theory, all matter is composed of indivisible atoms.
- Democritus first proposed the idea of indivisible atoms, later scientifically expanded by Dalton.
Practical Applications
- Individual atoms can be observed using scanning tunneling microscopes.
- Understanding atomic structure helps explain why elements differ, primarily due to their unique numbers of protons.
Atomic Composition
- For an element with atomic number 42, it contains 42 protons and electrons in a neutral atom.
- An isotope like krypton-84 has an atomic mass of 84.
- For an atom with atomic number 45 and mass number 92, it has 45 protons, 45 electrons, and 47 neutrons.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge of atomic structure with these flashcards covering key terms and definitions from Chapter 4. Learn about atoms, nuclei, electron clouds, and more essential concepts in chemistry.