In the 19th century, did scientists know the structure of atoms?
In 1863, Newlands proposed his...
Law of octaves
Theory of evolution
Law of structures
What did the law of octaves state?
8 keys in a piano is an octave
Similar properties are repeated every 8th element
8 elements are a group
Why was Mendeleev's periodic table better than Newlands?
He left gaps for undiscovered elements
He discovered the missing elements
He discovered the structure of an atom
Elements are arranged in the periodic table in order of their atomic numbers
Why do elements in the same group have similar chemical properties?
They follow Newlands law of octaves
Their atoms have the same number of electrons in their outer shell
When metals react they lose electrons so...
The reactivity of metals in a group increases going down the group
The reactivity of metals in a group decreases going down the group
When non-metals react they gain electrons so the reactivity of non-metals decreases going down the group
Group 1 elements are called the...
Acid metals
Alkali metals
They react readily with...
Air and water
hydrogen
Alkali metals have low melting and boiling points that decrease going down the group
Alkali metals react with water to produce hydrogen gas and...
Oxygen
A metal hydroxide
Group 1 metals form ionic compounds in reactions
Why does reactivity increase going down group 1?
The outer electron is less strongly attracted to the nucleus as the number of shells increase and the atoms get larger
The outer electron is more strongly attracted to the nucleus as the number of shells increase and the atoms get larger
Transistion elements are...
Bad conductors of heat
Malleable, ductile and good conductors of heat
Not malleable and hard to bend
Do transition elements react slowly or quickly with oxygen and water?
Quickly
Slowly
Are transition elements useful as building materials?
No because they are weak
Yes because they are strong and dense
Compounds of transition elements are...
Dull colours
Brightly coloured
Transition elements form positive ions
Which group are the halogens?
Group 1
Group 4
Group 7
Fill in the gap: Fluorine is a ........................................... at room temperature
Pale yellow gas
Yellow solid
Chlorine is a green gas at room temperature
Bromine is a green liquid at room temperature
Iodine is a grey solid at room temperature that easily vapourises to a violet gas
How do halogens bond with metals and non-metals?
Metals: Form an ionic compound Non-metals: Bond covalently to form molecules
Metals: They don't bond with Non-metals: Form an ionic compound
Why does the reactivity of the halogens decrease going down group 7?
The attraction of the outer electrons to the nucleus increases as the number of occupied shells increase
The attraction of the outer electrons to the nucleus decreases as the number of occupied shells increase
