How many significant digits are present in the number 0.02560? ...

[jparksx]

How many significant digits are present in the number 0.02560?
 
  A) 3
  B) 4
  C) 5
  D) 6

Question 2

It is relatively easy to pull an electron away from a potassium atom (K, atomic number 19), but very difficult to remove a second one because ________.
 
  A) of the repulsions occurring between electrons within the same shell
  B) the electrons are so very small
  C) of a much greater effective nuclear charge
  D) very little energy remains after the first electron is removed

[shewald78]

Answer to Question 1

B

Answer to Question 2

C

[jparksx]

Gracias!

[nguyenhoanhat]

Excellent