Answer:
The electronic configuration of the element with Atomic number 19 is 2,8,8,1. The element is potassium. It is an alkali metal with one valence electron.
Answer:
Earth's atmosphere is divided into five main layers: the exosphere, the thermosphere, the mesosphere, the stratosphere and the troposphere.
Explanation:
Answer:
Option D = No, when elements combine to form a new material, they have properties unique to the new materials.
Explanation:
When sodium contact with water it loses its one electron and thus gain positive charge. When there are more sodium atoms present and many atoms do this thus more positive ions are produced and these positive ions repeal each other at high speed and explosion occur.
But when it form compound with other material, it will not showed this behavior.
Example:
Consider the sodium chloride, when it dissolve in water sodium not showed explosion. In sodium chloride sodium already gives its electron to the chlorine and have stable electronic configuration. The sodium present in cationic form. When it dissolve, partial positive charge of water surrounds the Cl⁻ and partial negative charge of water surrounds the Na⁺ ion, ans sodium chloride gets dissolve into water without explosion.
Explanation:
When solid cadmium sulfide reacts with an aqueous solution of sulfuric acid then the reaction will be as follows.

Hence, ionic equation for this reaction is as follows.

Therefore, net ionic equation for this reaction is as follows.

The average speed of the blocks are 0.36 m/s.
Explanation:
Average speed is defined as the ratio of distance covered per unit time. So if it is said that blocks are pulled to 0.9 m in the right side. This means the blocks cover a distance of 0.9 m from the origin and that distance is covered in 2.5 s. Thus, the average speed can be calculated from the change in speed with respect to time. As at time t = 0 , the speed is also zero, and at time t = 2.5 s , the speed will be
Since, in this case, the speed is equal to the average speed of blocks. So the average speed of the blocks will be 0.36 m/s.