Structure of an Atom Flashcards
What is the nucleus?
Located in the center of an atom. Consists of protons and neutrons. Electrons surround the nucleus.
What is the center of an atom?
The nucleus.
What does the nucleus consist of?
Protons and neutrons.
What surrounds the nucleus?
Electrons
What is an atom?
Smallest piece of a matter that still has the properties of the element.
What is an element?
Matter that is composed of one type of atom.
How are elements abbreviated?
Elements are abbreviated in scientific shorthand - either a letter or a pair of letters call chemical symbols.
What are chemical symbols?
Letter or pair of letters used as scientific shorthand for elements. Examples: aluminum (Al) and copper (Cu).
Describe a proton.
It is part of the nucleus of an atom. It has a positive charge.
Describe an neutron.
It is part of the nucleus of an atom. It has a neutral or no charge.
Describe an electron.
They surround the nucleus of an atom. it has a negative charge.
What is a quark?
Smaller particles that make up protons and neutrons.
What are the six types of quarks?
Up, down, charm, strange, top, bottom. They are also known as flavors.
What are valence electrons?
Electrons in the outermost shell, or energy level, of an atom.
How do you determine the number of valence electrons in a given element?
Look at the “group” within the Periodic Table. Within a group, the number of valence electrons remains the same. For example, hydrogen, lithium and sodium all have 1 valence electron. Flurine, chlorine and bromine have 7 valence electrons.
What are the exceptions related to valence electrons?
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What is the electron clound?
Also called “Quantum Model”, it is a model that shows electrons travelling in specific energy levels around a nucleus. Electrons closest to nucleus have low energy and electrons further away from nucleus have high energy.
Where are low energy electrons located?
Closest to the nucleus.
Where are high energy electrons located?
Farthest from the nucleus.
What is a Quantum Model?
Same as an electron cloud. It is a model that shows electrons travelling in specific energy levels around a nucleus. Electrons closest to nucleus have low energy and electrons further away from nucleus have high energy.
What is Atomic Mass?
Composed mostly of protons and neutrons in the nucleus. The approximate number of protons and neutrons in the atom.
What is Atomic Number?
The number of protons in an atom. The number of protons also identifies the element.
What is Average Atomic Mass?
The weighted average mass of an element’s isotopes.
Compare Atomic Mass vs. Atomic Number vs. Average Atomic Mass.
Atomic mass is associated with the number of neutrons and protons that are present in a nucleus. Atomic number is usually the number of protons in the nucleus. Average atomic mass is the weighted average of an element’s isotopes.
