Krypton. The atomic radius decreases as you go across a period.
Slow chemical change
It is a chemical change because the erosion is due to the chemical reaction between the acid and the in the rain and the calcium carbonate.
It is slow due to the concentration of acid is low.
The percent concentration of a solution can be calculated from; mass of solute /mass of solution * 100. The mass of the solute here is 8.1 g.
<h3>What is concentration?</h3>
The term concentration refers to the amount of solute presnt in a solution. There are many ways of expressing concentration such as molarity, molality and percentage.
Here;
mass of solution = 230.5 g
Percent of solute = 3.5 %
3.5 = x/ 230.5 * 100
3.5 = 100x/230.5
230.5(3.5) = 100x
x = 230.5(3.5) /100
x = 8.1 g
Learn more about percent concentration: brainly.com/question/202460?
Answer:
En el caso del sodio, la valencia es 1, ya que tiene un solo electrón de valencia, si pierde un electrón se queda con el último nivel completo.
Explanation:
Grupo de la tabla periódica Electrones de valencia
Grupo 14 (IV) (Grupo del carbono) 4
Grupo 15 (V) (Grupo del nitrógeno ) 5