This question is about the element calcium.
Use words from the box to complete the sentences about calcium. Each word may be used once, more than once, or not at all.
| electrons | negative | neutral | neutrons |
| nucleus | positive | protons | shells |
An atom of calcium has a central __________ that contains particles called __________ and __________. Around these particles there are __________ orbiting in __________.
An atom of calcium has no charge because it contains equal numbers of __________ and __________.
The particles with the lowest mass in an atom of calcium are called __________.
Calcium forms a compound with the formula Ca3(PO4)2\text{Ca}_3(\text{PO}_4)_2Ca3(PO4)2.
How many different elements are there in Ca3(PO4)2\text{Ca}_3(\text{PO}_4)_2Ca3(PO4)2?
What is the total number of atoms in the formula Ca3(PO4)2\text{Ca}_3(\text{PO}_4)_2Ca3(PO4)2?
