If the element have 39 protons, that means that his atomic number is 39, being Yttrium the element. And, the number of protons is the same of the number of electrons, so, 39 electrons.
The atmosphere of earth is made of five main layers.
1) Troposphere : This is the lowest part of the atmosphere. Most of the air that makes up the atmosphere is present in this layer.
2) Stratosphere : This layer is present above troposphere and extends up to 50 km. It contains ozone layer which prevents the harmful ultraviolet rays from the sun from entering the lower troposphere
3) Mesosphere : The layer above stratosphere is known as mesosphere.
4) Thermosphere : The region lies above mesosphere.
5) Exosphere : The is the outermost region of the atmosphere.
From the above discussion we can see that the layer that lies between exosphere and mesosphere is Thermosphere
<span>Mg + O2 > MgO. In reactant side, 2 O atoms and 1 Mg are present. In product side, 1 Mg and O atoms are present. Put 2 in product side to balance O atoms and 2 at Mg in reactant side to balance Mg atoms. Therefore the balanced equation becomes, 2Mg + O2 ----> 2MgO. Hope it helps.</span>
B I hope it’s right I don’t really help a lot but yeah lol
