Revision Flashcards
?
What is the definition of an atom?
The smallest particle of an element that can exist
What is the definition of a compound?
Two or more atoms chemically bonded together, or, a substance made up of 2 or more different chemical elements combined in a fixed ratio.
What is the definition of an element?
Substances that contain only one type of atom.
What is the definition of pure?
A substance that contains only one element or compound.
What is an element?
A substance that cannot be broken down into simpler substances by chemical means.
What is a compound?
A substance formed when two or more elements chemically bond together.
True or False: Water (H2O) is a compound.
True
What is the smallest unit of an element?
An atom.
What are the two main types of substances in chemistry?
Elements and compounds.
True or False: All compounds are made of two or more different elements.
True
What is the periodic table?
A table that organizes all known elements by their atomic number and properties.
What do we call the vertical columns in the periodic table?
Groups or families.
What are the horizontal rows in the periodic table called?
Periods.
Which element is represented by the symbol O?
Oxygen.
True or False: Helium is a metal.
False
What is a chemical bond?
A force that holds atoms together in a compound.
What is a mixture?
A combination of two or more substances that are not chemically bonded.
True or False: Air is a compound.
False
What is the main difference between an element and a compound?
An element is a pure substance, while a compound consists of two or more different elements chemically combined.
True or False: Sodium (Na) is a non-metal.
False
True or False: Compounds can be separated by physical means.
False
What is the main gas in the Earth’s atmosphere?
Nitrogen - 78%
True or False: All elements have unique atomic numbers.
True
Fill in the blank: The most abundant element in the universe is ______.
Hydrogen
