Chemistry Flashcards
What does the atomic number determine?
The atomic number can allow us to identify the number of protons in an element.
What does the atomic mass tell us?
The atomic mass determines the total amount of protons and neutrons in an element.
What causes an atom to become a negative ion?
If an atom gains electrons, it is considered a negative ion or ‘anion’.
What causes an atom to become a positive ion?
When an atom loses an electron, it becomes a positive ion or ‘cation’.
What is graphite an example of?
Graphite is a non-metal.
What is the purpose of a pH scale?
The pH scale measures the amount of hydrogen (H+) ions in a solution to determine whether it is acidic or basic.
What pH does an acid have?
An acid has a pH less than 7.
What pH does a base have?
A base has a pH level over 7.
What are some properties of acids?
Acids:
- have a pH less than 7
- turns blue litmus paper red
- releases hydrogen ions into solution
- are corrosive
What are some properties of bases?
Bases:
- have a pH more than 7
- turns red litmus paper blue
- releases hydroxide ions into solution
- are caustic or corrosive
What is an alloy?
An alloy is a metal made by combining two or more metallic elements. E.g. brass, steel and copper.
What is a metalloid?
A metalloid is an element whose properties are a mix of both metals and non-metals. E.g. boron, silicon and arsenic
What is an element?
An element is a substance made up of one type of atom.
What is an allotrope?
Allotropes are the different physical forms in which an element can exist ie. diamond, graphite and charcoal are allotropes of carbon.
What does it mean when a substance is called ‘ductile’?
Substances which are considered ‘ductile’ can be stretched into wires without breaking. Examples of ductile substances are gold, silver and copper.
What happens to the pH of a substance when water is added to it?
The pH will rise since water dilutes the acid - making it more basic. Water also contains hydrogen which what is measured by the pH scale.
What is the balanced chemical equation of photosynthesis?
6CO_2 + 6H_2O = C_6 H_12 O_6 + 6O_2
What is the worded equation for photosynthesis?
Carbon dioxide + water = glucose + oxygen
What is the worded equation for a combustion reaction?
Methane + oxygen = carbon dioxide + water
What is the worded equation for corrosion?
Metal + water + oxygen = rust (metal oxide)
What is the worded equation of a reaction with acid and carbonate?
Acid + carbonate = salt + water + carbon dioxide gas
What is the worded equation for the reaction with acid and metal?
Acid + metal = salt + hydrogen
What is the equation for neutralisation?
Acid + base = salt + water
How do you find the group that an element belongs to?
You must find the electron configuration of the element and the number of electrons in the outermost shell is its group number.
