Chemistry Fundamentals Flashcards
Define an element
How many are there?
Substance made up of only one type of atom
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What links elements in the same periodic table group?
They have the same number of electrons in their highest energy level (outer shell), which gives them similar properties
Describe the structure of an atom
A small central nucleus made up of protons and neutrons, surrounded by shells of electrons
Relative atomic charges for protons, neutrons and electrons
P: +1 N: 0 E: -1
What’s the relationship between the atomic number, number of protons and number of electrons in an atom?
They are the same.
Define the mass number.
The sum of the protons and neutrons in an atom.
Explain why the noble gases are different to all other elements.
They have a complete outer shell, so they are un-reactive.
How is an ionic compound formed?
When a metal reacts with a non-metal, the metal looses electrons to form positively charged ions. The non-metal gains electrons to form negatively charged ions. The oppositely charged ions attract each other strongly and the compound has ionic bonds.
How are molecules formed?
When non-metals combine they share electrons to form covalent bonds and molecules are formed.
Why must a symbol equation be balanced?
Mass is conserved, as atoms are neither created nor destroyed.
What does the chemical formula of a compound tell us?
The simplest ratio of ions in the compound.
What does the chemical formula of a molecule tell us?
The number of atoms that have bonded together in the molecule.
