Answer:
For example, atoms in Groups 1 and 2 have 1 and 2 valence electrons, respectively. Atoms in Groups 13 and 18 have 3 and 8 valence electrons, respectively. Valence electrons are responsible for the reactivity of an element. They determine how "willing" the elements are to bond with each other to form new compounds.
Explanation: it might be 18 my guess:)
It is typically formed by the evaporation of salty water (such as sea water) which contains dissolved Na+ and Cl- ions. One finds rock salt deposits ringing dry lake beds, inland marginal seas, and enclosed bays and estuaries in arid regions of the world
Answer:
Catalysts help in increasing rates of reactions
Answer:
4 calcium ions and 4 sulfide ions.
Explanation:
In a face centered unit cell, 8 corners of the unit cell are occupied by 8 atoms. Each corner is 1/8 of a cell. In addition it has 6 atoms in the face of the lattice, which is 1/2 of a cell. (1/8 * 8) + (1/2 * 6) = 4. CaS has a 1:1 ratio. Therefore, they each have 4 ions.