Step 1: Foundations Flashcards
(26 cards)
What is the smallest unit of matter?
an atom
What is the center of an atom called
nucleus
what does a nucleus contain
protons, neutrons, and electrons
What defines an element
pure substance made of one type of atom
can an element be broken down into simpler parts?
no
what is an element defined by
the number of protons it has
where can you find elements
they’re listed on the periodic table
what is a proton?
A positively charged particle
what is a neutron?
A neutral particle found in the nucleus of an atom
what is an electron?
A negatively charged particle that moves around the nucleus
what does the periodic table organize elements based on?
their atomic number, electron configurations, and recurring chemical properties.
what is the atomic number?
the number of protons in the nucleus of an atom. It defines the element.
how does the atomic number relate to the periodic table?
Elements are arranged in order of increasing atomic number on the periodic table.
What is an electron configuration?
the arrangement of electrons in an atom’s orbitals, based on energy levels.
What is an energy level in an atom?
a region around the nucleus where electrons are likely to be found. Each level can hold a certain number of electrons.
What does an orbital mean in an atom?
a specific region within an energy level where electrons are most likely to be found. Each orbital can hold up to two electrons.
How many orbitals are in each energy level?
The number of orbitals increases as you go to higher energy levels:
How do electrons fill orbitals in an atom?
starting with the lowest energy level. Each orbital can hold two electrons, and they must have opposite spins.
What is a compound?
a substance made of two or more different elements chemically bonded together in fixed proportions.
What is a mixture?
a combination of two or more substances that are not chemically bonded and can be separated by physical means.
What is the difference between a compound and a mixture?
a compound has elements chemically bonded together, while a mixture has elements or compounds mixed but not chemically bonded.
What is a molecule?
two or more atoms chemically bonded together. It can be made of the same element or different elements
Can a molecule be a compound?
Yes! A compound is always a molecule, but not all molecules are compounds
What is an example of a compound?
Water (H₂O) is a compound made of hydrogen and oxygen atoms chemically bonded together.
