1. What is the middle layer of the earth?
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Other questions in this quiz
2. The atomic number of an element is equal to the number of ...?
- protons in the nucleus
- protons in the nucleus of its atoms
- electrons around the atom
3. the earths limited resouces come from..?
- its crust , the oceans and the atmosphere
- the volcanoes
- the air particles that form layers on the earths atmosphere
4. There are about .... different elements from which all substances are made?
5. How are elements arranged in the periodic table?
- in order of their atomic numbers
- in size order
- in the popularity