THE PERIODIC TABLE Flashcards
What is an element?
An element is a substance that contains only one type of atom. It cannot be broken down into other substances.
How many naturally occurring elements are there?
There are 98 naturally occurring elements.
How many elements does a smartphone typically contain?
A smartphone contains around 60 of these elements.
What is a chemical symbol?
A chemical symbol is a one- or two-letter code for an element used by scientists worldwide.
What is the chemical symbol for gold?
Au
What is the chemical symbol for iron?
Fe
True or False: An element can exist as a mixture.
False
Name three elements found in a smartphone.
- Gold (Au)
- Lithium
- Indium
Fill in the blank: The chemical symbol for magnesium is _______.
Mg
Why is it important to use the same chemical symbols across different languages?
- Consistency in scientific communication
- Reduces confusion among scientists globally
What happens when a substance is melted and electricity is passed through it, resulting in two different substances?
The substance cannot be an element because it breaks down into different substances.
What do the chemical symbols of some elements derive from?
Their Latin names, for example, aurum for gold and ferrum for iron.
What is the mass of gold in a typical smartphone?
0.025 g
Calculate the number of smartphones needed to contain a total of 1 g of gold.
40 smartphones
What is the approximate price of gold per gram?
£30
How many phones would contain £1000 worth of gold?
Approximately 33 smartphones
What is the correct format for writing a chemical symbol?
The first letter is uppercase and the second letter is lowercase, e.g., Mg.
List the chemical symbols for hydrogen, aluminium, magnesium, and sodium.
- Hydrogen - H
- Aluminium - Al
- Magnesium - Mg
- Sodium - Na
What elements are used in touchscreens?
- Indium
- Tin
- Oxygen
What is a compound?
A compound is a pure substance made up of atoms of two or more elements that are strongly joined together.
How is a water molecule structured?
A water molecule has one oxygen atom joined to two hydrogen atoms.
How does the property of a compound differ from its constituent elements?
The properties of a compound are different from the properties of the elements it is made up of.
What is the scientific name for salt?
Sodium chloride.
What elements make up salt?
- Sodium
- Chlorine
Describe the state and properties of sodium at room temperature.
Sodium is a shiny metal that is solid at 20 °C and reacts vigorously with water.
Describe the state and properties of chlorine at room temperature.
Chlorine is a smelly green poisonous gas at 20 °C.
Why does salt not smell or react like its constituent elements?
In salt, the atoms of sodium and chlorine are joined together to make one substance, sodium chloride, which has different properties.
What is a molecule?
A molecule is a group of two or more atoms strongly joined together.
Which has a higher boiling point, water or hydrogen?
Water has a higher boiling point than hydrogen.
What are the boiling points of oxygen and water?
- Oxygen: -183 °C
- Water: 100 °C
What forces hold molecules together in liquid hydrogen compared to liquid water?
Weak forces hold molecules close to each other in liquid hydrogen, while stronger forces hold molecules close together in liquid water.
Fill in the blank: A compound is a substance made up of atoms of _______ elements.
[two or more]
Fill in the blank: The properties of a compound are _______ to the properties of its elements.
[different]
Fill in the blank: A molecule is a group of _______ atoms strongly joined together.
[two or more]
What is tooth enamel composed of?
- Calcium
- Phosphorus
- Oxygen
Explain why water has different properties than hydrogen and oxygen.
Water molecules are made up of atoms of two elements, hydrogen and oxygen, which results in different properties from the individual gases.
What are the three classifications of substances?
Element, mixture, compound
What are the two types of particles that can make up a substance?
Molecules or atoms
What is the chemical formula of carbon dioxide?
CO2
What two elements make up carbon dioxide?
Carbon and oxygen
What is carbon monoxide and why is it dangerous?
A compound made of carbon and oxygen; it is poisonous and can be deadly
How much carbon is present in carbon dioxide compared to oxygen?
12 g of carbon for every 32 g of oxygen
How much carbon is present in carbon monoxide compared to oxygen?
12 g of carbon for every 16 g of oxygen
What is the name of the compound formed from aluminium and oxygen?
Aluminium oxide
What is the name of the compound formed from zinc and oxygen?
Zinc oxide
What is the formula of water?
H2O
Which compound has a higher proportion of oxygen: water or nitrogen dioxide?
Depends on the calculation of the mass ratios
What is the chemical formula of sodium chloride?
NaCl
What happens to the name of a non-metal in a compound with a metal?
The non-metal’s name ends with -ide
What is a chemical formula?
It shows the elements present and their relative number of atoms in a compound
What is the formula of sodium hydroxide?
NaOH
What does a hydroxide compound include?
Hydrogen and oxygen atoms
What is the formula of sodium nitrate?
NaNO3
What elements make up copper sulfate?
Copper, sulfur, and oxygen
Fill in the blank: The formula of carbon dioxide is _______.
CO2
What is the formula for potassium hydroxide?
KOH
What is the formula of calcium carbonate?
CaCO3
True or False: The formula of carbon monoxide is CO.
True
Name the elements in the compound with the formula H2O.
Hydrogen and oxygen
What does the term ‘relative number’ mean in the context of chemical formulas?
How many of one type of atom there are compared to another
What is the formula for sulfur dioxide?
SO2
What does a particle diagram represent?
Atoms, molecules, elements, mixtures, and compounds
What is a polymer?
A polymer is a large molecule made up of identical groups of atoms repeated many times.
Give examples of natural polymers.
- Wool
- Starch
- Rubber
- Chitin
What is chitin and where is it found?
Chitin is a polymer that forms the exoskeletons of lobsters, cockroaches, and ants.
How do polymer properties depend on their molecules?
The properties of a polymer depend on its molecules, which are relatively big and heavy, resulting in higher melting temperatures.
What is the melting temperature of methane?
-182 °C
What are the melting temperature ranges for poly(ethene)?
Between 105 and 180 °C
Why does methane melt at a lower temperature than poly(ethene)?
Methane has smaller molecules compared to poly(ethene), leading to lower melting temperatures.
What properties make wool useful for clothing?
Wool fibres trap air, which traps heat.
What is a primary use of rubber?
Rubber is primarily used to make tyres.
What are synthetic polymers?
Synthetic polymers are man-made polymers produced through chemical reactions.
What are the two types of poly(ethene)?
- Low-density poly(ethene) (LDPE)
- High-density poly(ethene) (HDPE)
What is a key property of low-density poly(ethene) (LDPE)?
LDPE is flexible and strong.
What is a key property of high-density poly(ethene) (HDPE)?
HDPE is harder than LDPE and can have very smooth surfaces.
Why is it important that poly(ethene) does not decay naturally?
This property is important for artificial knee joints but makes it hard to dispose of carrier bags.
What is the density of low-density poly(ethene)?
0.92 g/cm³
What is the density of high-density poly(ethene)?
0.96 g/cm³
Fill in the blank: A polymer has _______ molecules.
[large]
Fill in the blank: There are two types of polymer: _______ polymers and _______ polymers.
[natural, synthetic]
Why is low-density poly(ethene) suitable for carrier bags?
Because its molecules slide over one another, making it flexible.
Which polymer is suitable for packaging due to its properties?
Polystyrene
What property of polystyrene makes it suitable for disposable cups?
Low density
