Predict the physical properties and relative reactivity of
Ba and Sr
Cs and Br
( elements from periodic table )
Please help.. it's urgent.
To predict the physical properties and relative reactivity of the elements Ba (barium) and Sr (strontium), as well as Cs (cesium) and Br (bromine), we can look at their positions in the periodic table.
Ba and Sr are both alkaline earth metals, belonging to Group 2 elements. They have similar physical properties due to their common group. Some of their physical properties include:
1. Metallic character: Ba and Sr are both highly metallic elements. This means they have shiny luster and are good conductors of heat and electricity.
2. Melting and boiling points: They have relatively high melting and boiling points compared to non-metals.
3. Density: Both Ba and Sr have relatively high densities.
4. Atomic size: Ba has a larger atomic size than Sr because atomic size generally increases as you move down a group in the periodic table.
In terms of reactivity, Ba and Sr are both highly reactive metals. They readily react with water and oxygen. However, their reactivity decreases as you move down the group. So, Sr is slightly less reactive compared to Ba.
Now, let's consider the elements Cs and Br.
Cs is an alkali metal belonging to Group 1 in the periodic table, whereas Br is a halogen belonging to Group 17. Let's look at their physical properties and relative reactivities:
1. Physical properties:
- Cs: Cs is a soft, silvery-white metal that is highly reactive.
- Br: Br is a reddish-brown non-metal that exists as a diatomic molecule (Br2) in its elemental form. It is a liquid at room temperature.
2. Reactivity:
- Cs: Cs is the most reactive metal among the alkali metals. It is highly reactive, easily losing its valence electron to form Cs+ ions.
- Br: Br is a highly reactive non-metal that readily accepts an electron to form Br- ions.
In terms of reactivity, Cs is more reactive than Br because alkali metals are more reactive than halogens. Cs reacts explosively with water and undergoes vigorous reactions with other elements. On the other hand, Br readily reacts with metals to form ionic compounds called bromides.
Overall, Ba and Sr have similar physical properties and reactivity as alkaline earth metals, with Ba being slightly more reactive than Sr. Cs is a highly reactive alkali metal, whereas Br is a reactive halogen.