S orbital.
Group 1 elements have a general configuration 
, where n represents the highest occupied Principal Energy Level. For example, Lithium has the valence configuration 
whereas Cesium has 
. Both of them belong to Group 1 of Periodic Table.
Group 2 elements have a general configuration of 
. For example, Magnesium has 
as its outer shell configuration while Strontium has the same as 
.
We see that in both the cases, the outermost S orbital is being filled.
Temperature difference is required, so i’m guessing - a. thermometer - would be required to check that temperature.
Answer:
<h2>compression</h2>
Explanation:
Such type of the longitudinal waves that causes compression during the travelling through the medium is called as compression. Generally, displacement of the medium takes place in this wave travelling conditions. There are many waves that are considered as longitudinal waves such as sound waves, seismic p-waves and some other. Waves have different types of properties that are changed due to different medium.
How bright a star appears from Earth is the star's apparent magnitude.
Answer:
I will answer in English.
Here we will use the relation
Velocity*time = distance
So:
a) velocity = 3m/s
time = 2s
Distance = 3m/s*2s = 6m
b) velocity = 2m/s
time = 3.5s
Distance = 2m/s*3.5s = 7m
c) velocity = 10m/s
time = 0.5s
Distance = 10m/s*0.5s = 5m
d) velocity = 4m/s
time = 2.5s
Distance = 4m/s*2.5s = 9m
e) velocity = 1.5m/s
time = 5s
Distance = 1.5m/s*5s = 7.5m
