Any element from group 1 of the Periodic Table.
Answer:
M (third main energy level)
Explanation:
The third main energy level bears the first appearance of the 'd' sublevel. The principal quantum number(n) depicts the main energy levels in which an orbital is located. It takes values of n=1,2,3,4,5..... and it can be represented by the shells k,l,m,n.......
The subshells in these main orbitals are represented by s,p,d and f. For the K shell, the principal quantum number is m and its sublevel notations are s,p and d. This is where the d-sublevel first appears.
Answer:
The acceleration of the car is 9,19 m/s2
Explanation:
We use the formula: F=m x a---> a=F/m
a=21,6N/ 2,35kg 1N is 1kgxm/s2
a=21,6 kg x m/s2 x 2,35 kg
a=9,191489362 m/s2
A neutral atom of potassium has 19 electrons.
