Periodic table Flashcards
All substances have properties. These describe how a substance __ and __ .
There are two types of properties: __ and __ .
looks
behaves
physical
chemical
When liquid water boils, it produces steam. Is this a physical or chemical reaction?
It is a physical reaction because it changes state.
Why are electrical cables coated in plastic?
The plastic acts as an electrical insulator, meaning we can touch the outside of electrical plugs and wires without getting a shock. Plastic is also ductile, which means it can stretch and bend with the wires.
What is a chemical property?
Chemical properties - chemical changes happen when chemical reactions occur. They involve the formation of new chemical elements or compounds.
What is a physical property?
Physical properties - in a physical change, a substance simply changes physical state. For example, from a solid to a liquid.
Most cooking pans are made from aluminium and steel. This is because a property of aluminium and steel is that they are excellent __ of heat.
conductors
True or false? Water changes from a liquid to a gas during evaporation, which is an example of a chemical change.
False! Evaporation is a physical change.
This is because physical changes occur when a substance simply changes physical state, such as from a liquid to a gas.
Physical properties can be __ and can usually be __ quite easily in an experiment.
seen
measured
By applying force to an object you can observe it’s physical properties. If something is ___ the object may snap, or if it is flexible the object will __ .
brittle
bend
By observing a solid’s __ point, or a liquid’s __ point these physical properties can be measured.
melting
boiling
Water goes through different physical changes. Are any of these physical changes permanent?
No, water doesn’t permanently change physical state.
Water that has been boiled and changed state to a gas (evaporation) can cool down and return to its liquid state (condensation).
Chemical changes happen when chemical reactions occur. However, the properties__ be learnt just by looking at, touching or taking a simple measurement of the substance.
cannot
A substance has a melting point of -25°C and a boiling point of -1°C. What state is it at -5°C?
Liquid.
All elements are arranged in a chart called the __ .
periodic table
The arrangement of elements in the periodic table is based on their __ and.
structure
properties
A Russian scientist named __ produced one of the first practical periodic tables in the 19th century.
Dmitri Mendeleev
The modern periodic table is based closely on the ideas of Dmitri Mendeleev.
These ideas were: (4)
- The elements are arranged in order of increasing atomic number
- The horizontal rows are called periods
- The vertical columns are called groups
- Elements in the same group are similar to each other
Why did Mendeleev leave gaps in his original periodic table?
Because he recognised that not all elements had been discovered.
During Mendeleev’s time there were around only 65 known elements. Today we know there are 118 elements, all which can be found on the modern periodic table.
The most recent element to be discovered is __ which was made in a laboratory in 2009.
This element only exists for fractions of a second, because it is unstable meaning it breaks apart very quickly.
Tennesine
The periodic table is arranged in rows called __ and columns called __ , which can be used to locate any element.
periods
groups
Can water be found in the periodic table?
No.
Water is a compound, H₂O. The periodic table is made up of elements.
In the modern periodic table:
The elements are arranged in order of ___
The horizontal rows are called __ .
The vertical columns are called __ .
Elements in the same group are __ to each other.
increasing atomic number.
periods
groups
similar
In the periodic table each square in the table contains an __ of one or two letters, not the element name.
element symbol
Hydrogen has lots in common with the metals in group 1, however, hydrogen is a gas so it can’t be a __ .
metal
Groups contain elements with similar __ properties and __ properties.
chemical
physical
For example, the metals in group 1 are all reactive, whereas the elements in group 0 are all unreactive gases.
The periodic table’s layout means we can make ___ about elements based on their position on the periodic table.
predictions
In the periodic table, what terms are used to describe a vertical column and horizontal row?
A vertical column is called a group, and a horizontal row is called a period.
The elements in group 2 share a similar chemical property in that they are all __ which react with __ . As you go down group 2, the metals become easier to melt. This is a pattern of a physical property.
metals
oxygen
The Group 1 elements are called the __ metals.
alkali
All the Group 1 elements are very __ , and all react with __ to produce an alkaline solution.
reactive
water
Group 1 elements have to be stored under __ to ensure air and water don’t react with them. This is because Group 1 metals are very reactive.
oil
Using the periodic trend of group 1 elements, can you predict how a small piece of potassium (K) will react when it is added to water?
When potassium (K) is added to water, the metal floats and fizzes violently. It melts and moves around very quickly on the surface of the water. The metal catches on fire, and some sparks are produced.
Therefore we can conclude that:
The reactivity of Group 1 elements increases as you go down the group.
The Group 7 elements are non-metals, known as the__ . They include the elements chlorine, bromine and iodine.
halogens
__ is the rarest naturally occurring element in the world. It is so rare that no-one has been able to measure its properties. __ is even rarer - only a few atoms of it have ever been made, in powerful nuclear reactors.
Astatine
Tennessine
True or false?
Calcium is a metal.
It’s true - calcium (Ca) is a metal!
We often hear about calcium being in milk and dairy products, but that is when the calcium atoms are chemically bonded to other atoms to form compounds.
Calcium is found on the left of the periodic table, surrounded by other metals. Calcium has the usual properties of a metal. For example it is a good conductor of heat and electricity.
Most elements in the periodic table are ___ , while
__ account for around 20% of known elements.
metals
non-metals
What type of elements make up around 20% of the periodic table?
Non-metals.
Properties of metals (7)
- They have high melting and boiling points meaning they are solid at room temperature
- They are good conductors of heat and electricity
- They are shiny in their appearance
- They are malleable
- They are hard and strong
- Have a high density
- They are sonorous
Do all metals share the same properties?
No. There are some exceptions.
For example, there are differences in properties between the group 1 metals and the transition metals, and mercury (Hg) is a metal which is a liquid at room temperature
What are the properties of non-metals? (5)
- Poor conductors of heat and electricity
- Dull in their appearance
- Weak and brittle
- Generally low melting and boiling points, meaning they are gases and liquids at room temperature
- Not sonorous
