Calcium has 2 valence electrons, so you get Ca++ ions. It can form compounds with most other elements (except members of its own group), and readily forms salts, with elements like the halides, also oxides form easily. An Inorganic Chem text, or google (try calcium salts ionic compounds), should tell you more. A salt is an ionic compound--solid salts form a regular crystal lattice.
Calcium salts are just like any other salts. The are formed by combining a metallic element - in this case, calcium - with a non-metallic element such as chlorine, fluorine, etc. Frud is correct, the halides form most of the common calcium salts. Take a look at the periodic table - calcium will form a salt with every non-metallic element listed save for the noble gasses. Just a bit of additional information: it will also combine it's crystalline structure with other metals and thus form alloys. One common application is adding it to lead to form a harder, tougher alloy than pure lead is alone.
How can i know which compounds calcium can form? Why are calcium salts formed by combining a metallic element with a non-metallic element? Why will calcium form a salt with every non-metallic element listed in the periodic table?
Try studying the group of elements that Ca belongs in, in the Periodic Table. This might help explain why Calcium forms the compounds it does (at least to some extent). There isn't any handy formula that tells you how a given element will behave, this has to be empirically determined. It's to do with electron affinity, bonding (covalent and ionic), etc, and the size of Ca++ ions, in part. You will need to study a bit of Chemistry to answer those questions you have.
Sort of. Atomic radius isn't necessarily constant. But a good inorganic chem text should outline more of the details. It's a pretty big subject: understanding Ca's chemistry is easier if you understand other elements in the same, and other groups, and various aspects of "combining" different elements. Or condensed matter physics. Ca is important in metabolic processes, and neural activity.
Depending on the conditions, calcium can form a salt with any nonmetal, that's was makes is a calcium salt. Are you confused about which calcium salts are soluble?
