Atoms, the Periodic Table Flashcards
(16 cards)
What is an atom?
The smallest piece of an element that still retains its chemical properties. It consists of a nucleus and an electron cloud.
What are the three subatomic particles that make up an atom?
Protons, neutrons, and electrons.
Where are protons and neutrons located, and what are their charges?
Both are located in the nucleus. Protons have a positive (+) charge, while neutrons are neutral (no charge).
What are the charge and approximate mass of an electron?
Electrons have a negative (–) charge and a mass close to 0 amu.
What does the atomic number represent?
The number of protons in an atom, which also equals the number of electrons in a neutral atom.
How is the mass number of an atom determined?
It is the sum of the number of protons and neutrons in the nucleus.
What are isotopes?
Different forms of the same element that have the same number of protons but different numbers of neutrons.
What is the electron cloud?
The region around the nucleus where electrons are located, organized into energy levels or shells.
How many electrons can the first, second, and third electron shells hold?
The 1st shell holds 2 electrons, the 2nd shell holds 8 electrons, and the 3rd shell holds 18 electrons.
What does a period represent on the periodic table?
A row on the periodic table; elements in a period have the same number of electron shells.
What defines a group (or family) on the periodic table?
A column where elements share a similar number of valence electrons, which influences their chemical behavior.
What are the characteristic properties of Alkali Metals?
They are in Group 1, have 1 valence electron, and are very reactive.
What are the characteristic properties of Alkaline Earth Metals?
They are in Group 2, have 2 valence electrons, and are reactive, though less so than alkali metals.
What are the key properties of Halogens?
Found in Group 17, they have 7 valence electrons, making them very reactive.
Why are Noble Gases considered non-reactive?
They have a full outer electron shell (except helium, which has 2 electrons), making them chemically inert.
What is unique about hydrogen’s placement in the periodic table?
Hydrogen stands alone; it doesn’t fit neatly into any group because it can either lose its one electron or share it through bonding.
