Atoms Flashcards
Atomic Structure and the Periodic Table (20 cards)
What is the radius of an atom?
About 0.1 nanometres (1 x 10^-10 m)
A nanometre (nm) is one billionth of a metre.
Where is the nucleus located in an atom?
In the middle of the atom.
What particles are contained in the nucleus?
Protons and neutrons.
What is the radius of the nucleus?
Around 1 x 10^-15 m (1/10,000 of the radius of an atom).
What type of charge does the nucleus have?
Positive charge due to protons.
Where is most of the mass of an atom concentrated?
In the nucleus.
What are the characteristics of protons?
Heavy and positively charged.
What are the characteristics of neutrons?
Heavy and neutral.
What are the characteristics of electrons?
Tiny and negatively charged.
Where do electrons move in an atom?
Around the nucleus in electron shells.
What determines the size of the atom?
The volume of the electron orbits.
What is the mass of electrons compared to protons and neutrons?
Electrons have virtually no mass.
What is the relationship between the number of protons and electrons in a neutral atom?
They are equal.
Why do atoms have no overall charge?
They have the same number of protons as electrons.
What is an ion?
An atom or group of atoms that has lost or gained electrons.
What happens to the charge of an ion?
The number of protons does not equal the number of electrons.
What does the atomic number represent?
The number of protons in an atom.
What does the mass number represent?
The total number of protons and neutrons in the atom.
How do you find the number of neutrons in an atom?
Subtract the atomic number from the mass number.
What is the nuclear symbol for sodium?
Na with atomic number 11.
