AQA GCSE Chemistry Paper 1

The image shows a single element from a full periodic table. The number at the top left....

• Is the Mass Number, which represents the number of protons in the nucleus

• Is the Atomic Number, which represents the number of electrons in the outer shell

• Is the Mass Number, which represents the number of protons and neutrons in the nucleus

• Is the Atomic Number, which represents the number of protons in the nucleus

The image shows a single element from a full periodic table. The number at the bottom....

• Is the Mass Number, which represents the number of protons in the nucleus

• Is the Atomic Number, which represents the number of electrons in the outer shell

• Is the Mass Number, which represents the number of protons and neutrons in the nucleus

• Is the Atomic Number, which represents the number of protons in the nucleus

Answer explanation

Normally the number is a whole number, or in the case of Chlorine, a precise half (35.5).

This periodic table shows a precise figure taking into account all the different isotopes of that element.

The image shows a single element from a full periodic table. The fact that the number at the bottom is not a whole number tells us....

• That we cannot measure it exactly

• That the number of protons in the nucleus can vary

• That Nitrogen has more than one isotope

The image shows a single element from a full periodic table. What can you deduce from the fact that the number at the bottom is slightly more than 14?

• That the most abundant isotope of Nitrogen is Nitrogen-14

• That all isotopes of Nitrogen have 6 or 7 neutrons

• That Nitrogen has only two isotopes

Answer explanation

We cannot tell how many other isotopes there are - nor what their mass numbers might be - from the combined mass number given. But we can say that the most common isotope is going to have the mass number 14.

In the periodic table....

• Metals are on the left, non-metals on the right

• The transition metals are at the far left

• Groups are columns, periods are rows

• Group 0 is at the far right end

Metal + acid forms....

• Salt and water

• Salt and oxygen

• Salt and Hydrogen

• Mineral and water

Answer explanation

But only for metals more reactive than Hydrogen. Metals like Copper, Silver and Gold will not react with an acid.

Mnemonic: MASH!

In ionic compounds....

[More than one correct answer]

• A metal combines with a non-metal

• A non-metal combines with another non-metal

• Atoms gain and lose electrons

• Atoms share electrons

• Delocalised electrons form a 'glue' between ions

In covalent compounds....

[More than one correct answer]

• A metal combines with a non-metal

• A non-metal combines with another non-metal

• Atoms gain and lose electrons

• Atoms share electrons

• Delocalised electrons form a 'glue' between ions

The best definition of an alloy is....

• A mixture of a metal with another metal or non-metal, that changes the physical properties of the metal

• An ionic compound including oxygen

• A pure metal

In terms of bonding and structure, graphite, diamond and silicon dioxide are examples of....

• Covalent, simple molecular substances

• Ionic substances

• Polymers

• Giant covalent substances