. An element has the electronic structure 2,8, 4. Which group is it in? A group 3
B group 4
C group 0​

Ans A

Explanation:

no. of shells determine the group

 None of the options

Explanation: 2, 8, 4 represents a total of 14  electrons.  

The 2:   1s^2

The 8:  2s^2 2p^6

The 4:   3s^2 3p^2

Assuming a neutral atom, 14 electrons represnt element #14, Silicon.  The electron configuration matches that of silicon,  But silicon is in group  14, which is not in the options.  It is a metalloid, so if there is another grouping system, use the nuimber assigned to the metalloids.  But the word "Group"normally refers to the column number, 14 for silicon.  And I've never heard of Group 0.  

First, he should measure how long it takes for the liquid to become clear if X and Y are mixed together. Then, he should measure how long it takes if he also adds substance A to X and Y. He will find out if substance A is a catalys

Explanation:

did the test rn