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
