Chemistry Flashcards
What is the atomic number of an atom?
The number of protons an atom has
What is the atomic mass or mass number of an atom?
The number of protons and neutrons an atom has
What is an ion?
An atom ore molecule that has gained or lost one or more of their valence electrons and therefore have a net positive or negative charge
What is an atom?
An incredibly small particle made of mostly empty space
What is an element?
A unique, pure chemical substance made of atoms of only one type
What is an isotope?
An atom with the same number of protons, but different numbers of neutrons
What does a compound contain?
Atoms of different elements chemically bonded together
What is a mixture made of?
Two or more substances that are not chemically combined
What does the Law of Conservation of mass state?
During chemical reactions, matter is neither created or destroyed
What is the main rule during all chemical reactions?
The total mass of products is always equal to the total mass of reactants
What are molecules?
Small groups of atoms chemically bonded together
What are the signs of a chemical reaction occurring?
Change in colour, change in temperature, formation of a precipitate, emission of light or production of gas
What are the columns of the periodic table known as?
Groups
What are the rows of the periodic table known as?
Periods
What do all elements in the same group contain?
Similar chemical properties and the same number of outer shell electrons
What do the left-hand and right-hand sides of the periodic table contain?
The left-hand side contains metals, whilst the right-hand side contains non-metals
What does the group number of the periodic table indicate?
The number of valence electrons an element has
What does the period number of the periodic table indicate?
The number of shells and element has
What is the electronic configuration?
The arrangement of electrons around the nucleus
What are outer shell electrons known as?
Valence electrons
How many electrons can the first electron shell, closest to the nucleus hold?
2 electrons
How many electrons can the second and third electron shells?
8 electrons each
What elements are found in group 1?
Alkali metals
What elements are found in group 2?
Alkaline earth metals
What elements are found in group 7?
Halogens
What elements are found in group 8?
Noble gases, which contain a complete outer shell of electrons
How many naturally occurring elements are there?
92 elements
How many artificially produced elements are there?
17 elements
How are elements in the periodic table arranged?
In order of increasing atomic mass
