KS3 Science Quiz - Atoms and Elements 04 (Questions)

This is our final KS3 Science quiz on atoms and elements. A chemical element is a pure chemical substance consisting of one type of atom. Each one has a symbol and a name and can be found on the periodic table. When you first look at a copy of the periodic table, it doesn't seem to follow any pattern - the elements are not placed in alphabetical order. But if you look more closely, you will see that each element has some numbers in the box with its name and symbol. If you look along a row of elements, you will soon notice that the number called the atomic number increases by one from one element to the next. This number tells you how many protons an atom of the element contains.

This pattern took scientists many years to work out. At first, the problem was that they didn't really understand the difference between elements and compounds.

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A French scientist made a list of what he believed to be the known elements. He was beheaded in the French revolution, so he didn't get any further, but it was a useful start for other scientists to work on. Several other scientists tried to make sense of the elements by grouping them together according to their chemical reactions. In the 1860s, a Russian scientist called Mendeleev, put a periodic table together, but left gaps where he thought there were missing elements. Other scientists though it was a daft idea, but, he had got it right and the periodic table we know today came from that. The periodic table contains about 118 elements so far, but this may very well increase if we discover more elements.

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1. A pure substance in which all of the atoms are identical is a description of .......
[ ] a compound
[ ] a mixture
[ ] an alloy
[ ] an element
2. In the periodic table, the elements are arranged in order of increasing .......
[ ] alphabetical symbol
[ ] electron number
[ ] mass number
[ ] proton number
3. The elements in group 7 of the periodic table are .......
[ ] conductors
[ ] gases
[ ] metals
[ ] non-metals
4. The name of the element with the symbol Na is .......
[ ] napthalene
[ ] neon
[ ] nickel
[ ] sodium
5. The name of a gas used in weather balloons is .......
[ ] chlorine
[ ] hydrogen
[ ] neon
[ ] nitrogen
6. Which of the following is a halogen?
[ ] Argon
[ ] Fluorine
[ ] Helium
[ ] Neon
7. Lithium floats on water as it .......
[ ] is a non-metallic element
[ ] is a solid
[ ] is less dense than water
[ ] is more dense than water
8. Li, Na, K and Cs are group 1 elements. The most reactive is .......
[ ] Cs
[ ] K
[ ] Li
[ ] Na
9. The following elements are named after countries except .......
[ ] Fr
[ ] Ge
[ ] I
[ ] Po
10. The following elements are named after famous scientists except .......
[ ] curium
[ ] einsteinium
[ ] nobelium
[ ] uranium
KS3 Science Quiz - Atoms and Elements 04 (Answers)
1. A pure substance in which all of the atoms are identical is a description of .......
[ ] a compound
[ ] a mixture
[ ] an alloy
[x] an element
Atoms of the same element have the same number of protons in the nucleus as each other
2. In the periodic table, the elements are arranged in order of increasing .......
[ ] alphabetical symbol
[ ] electron number
[ ] mass number
[x] proton number
Also called the atomic number, it also tells you how many electrons thare are in an atom
3. The elements in group 7 of the periodic table are .......
[ ] conductors
[ ] gases
[ ] metals
[x] non-metals
Group 7 is also referred to in some periodic tables as group 17 and the chemicals of this group are called the halogens
4. The name of the element with the symbol Na is .......
[ ] napthalene
[ ] neon
[ ] nickel
[x] sodium
This is a common symbol that you will come across dozens of times as you study science
5. The name of a gas used in weather balloons is .......
[ ] chlorine
[x] hydrogen
[ ] neon
[ ] nitrogen
Both hydrogen and helium are less dense than air. Helium is used in airships as it is unreactive and so safer than hydrogen (check out the Hindenburg disaster). Hydrogen, however, is still used in weather balloons as it is cheaper than helium
6. Which of the following is a halogen?
[ ] Argon
[x] Fluorine
[ ] Helium
[ ] Neon
The halogens are coloured elements - fluorine (symbol F) is a yellow-green gas
7. Lithium floats on water as it .......
[ ] is a non-metallic element
[ ] is a solid
[x] is less dense than water
[ ] is more dense than water
Lithium is a metal in group 1 of the periodic table, its atoms contain three protons
8. Li, Na, K and Cs are group 1 elements. The most reactive is .......
[x] Cs
[ ] K
[ ] Li
[ ] Na
The elements in group 1 increase in reactivity as you go down the group. You may have seen a video of this - caesium explodes and destroys the bowl of water
9. The following elements are named after countries except .......
[ ] Fr
[ ] Ge
[x] I
[ ] Po
Fr Francium - France, Po Polonium - Poland, Ge Germanium - Germany. There are several more!! I is the chemical symbol for iodine, a dark purple solid that is a member of the group of elements called the halogens
10. The following elements are named after famous scientists except .......
[ ] curium
[ ] einsteinium
[ ] nobelium
[x] uranium
Uranium was named after the planet Uranus