In an exothermic reaction, heat is produced along with products. But in endothermic reaction, heat is absorbed. If the number of products is less than the sum of the enthalpies of the reactants, the reaction will be exothermic. If the number of products is more than the sum of the enthalpies of the reactants, the reaction is endothermic.
Magnesium(?)
<span>2 HCl + Mg ? MgCl2 + H2</span>
Answer:
chemical
Explanation:
The chemical properties determine the identity of a substance and are not changed when there is no reaction. In the solution, what takes place is a physical change, which is a change of state (for example, going from solid to aqueous form).
Simple cations are formally called by their element names with a suffixed Roman numeral in parentheses to indicate its charge. A simple anion has a name that is the original elemental name with the final syllable changed to -ide.
Explanation:
1. Electrons surround the nucleus in defined regions called orbits.
2. The shells further away from the nucleus are larger and can hold more electrons.
3. The shells closer to the nucleus are smaller and can hold less electrons.
4. The closest shell (closest to the nucleus) can hold a maximum of two electrons.
5. Once the first shell is full, the second shell begins to fill. It can hold a maximum of eight electrons.
6. Once the second shell is full, the third shell begins to fill.
7. Once the third shell contains Eighteen electrons, the fourth shell begins to fill.
8. The arrangement of electrons in shells around the nucleus is referred to as an atom's electronic configuration.
