Answer:
longitudinal
Explanation:
the wave travels in the same direction as the movement from the person
Isotopes are atoms of the same element that<span> has different masses.</span>
Answer:
Option E, Half life = 
Explanation:
For a first order reaction, rate constant and half-life is related as:

Where,
= Half life
k = Rate constant
Rate constant given = 


So, the correct option is option E.
An x would represent the gained electrons
A . Would represent the valence electrons
You would just draw [ ] around the diagram
And the charge should be placed outside the brackets
Zeff is the effective nuclear charge wherein, Z resembles the number of protons in the nucleus while S corresponds to the number of non-valence electrons.
Zeff = Z - S
Silicon has 14 protons; its electron configuration is [Ne] 3s2 3p2. Its
non-valence electrons is in the n = 1 and n =2 shells. There are 2
electrons in n = 1 and 8 in n = 2, so there are a total of 10
non-valence electron.
<span><span>Z<span>eff</span></span>= 14−10= 4</span>
So, the answer is 4.