Atom Flashcards
What is an atom?
The building block of all things in the universe; the smallest unit of matter with characteristic properties of a chemical element
Atoms cannot be divided without releasing electrically charged particles.
What components make up an atom?
- Nucleus (protons and neutrons)
- Electrons arranged in shells around the nucleus
What charge do protons carry?
Positive charge
What charge do neutrons carry?
No charge (neutral)
What charge do electrons carry?
Negative charge
Where is most of the mass of an atom located?
In the nucleus
What is valency?
Describes how easily an atom or radical can combine with another chemical species, determined by the number of electrons gained, lost, or shared
How is valency represented?
By a positive or negative integer
What is a valence shell?
The outermost shell of an atom, containing valence electrons that participate in bonding
What are valence electrons?
Electrons present in the valence shell that can be lost, gained, or shared
What is an ion?
An atom or group of atoms that bears one or more positive or negative electrical charges
What are positively charged ions called?
Cations
What are negatively charged ions called?
Anions
What is a covalent bond?
A chemical bond involving the sharing of electrons between atoms to form electron pairs
What is a molecule?
A group of two or more atoms, such as a water molecule (H2O)
What defines an element?
A substance that cannot be broken down into any other substance, made up of unique types of atoms
What lists all known elements?
The periodic table
What is the only non-metallic element that is a liquid at room temperature?
Bromine
What is the chemical symbol for gold?
Au
Fill in the blank: Most solid elements are ______.
Metals
True or False: Most non-metallic elements are gases at room temperature.
True
