(2) argon. This is because Ca originally has 20 total electrons with a configuration of 2,8,8,2. When it looses its valence electrons it remains with 18 electrons total (2,8,8 config). Argon has 18 electrons total too (2,8,8 config).
First, lets examine the formula for that of Ammonia.
Ammonia = NH3
Notice that in the formula, there are 3 hydrogen atoms in a single ammonia molecule. This being said, if there are 200 molecules of ammonia in the given scenario, multiply 200 by 3.
× ← Amount of (H) Atoms Present in 200 (NH3) Molecules
Hope this helps!
Some people think its francium and some people believe it is either sodium or potassium.
Some people believe that the most reactive element is francium because the larger the atom, the easier it is to get rid of the valence electrons and the easier it is to react with other atoms. so now if you look at the periodic table, francium has the largest radius and so that's why some people think its francium. but in my opinion, Francium AND Cesium.
A physical change involves a change in physical properties. Examples of physical properties include melting, transition to a gas, change of strength, change of durability, changes to crystal form, textural change, shape, size, color, volume and density.