Because their electronic configurations have the same number of electrons in the outermost shell.
Answer : The de Broglie wavelength will be 
Solution :
The formula used for de Broglie wavelength is:
..........(1)
where,
= wavelength = ?
h = Planck's constant = 
m = mass = 1.2 g = 0.0012 kg
Conversion used : 1 kg = 1000 g
v = velocity = 150 m/s
Now put all the given values in equation 1, we get:


Therefore, the de Broglie wavelength will be 
Answer:
Explanation:
30+38
so this is the isosotope of Zn that weighs 68
-so Zn68
The atomic mass is useful in chemistry when it is paired with the mole concept: the atomic mass of an element, measured in amu, is the same as the mass in grams of one mole of an element. since the atomic mass of iron is 55.847 amu, one mole of iron atoms would weigh 55.847 grams.
The answers include the following:
- Graphite conducts electricity because it has delocalised electrons which makes it possible for the electrons to move freely.
- Graphite is slippery because it has layers which makes it possible for the atoms to slide over each other.
<h3>What is Graphite?</h3>
This is referred to as an allotrope of carbon and it is the most stable form. it is used in the production of substances such as pencil, electrode etc.
Graphite is able to conduct electricity because of the presence of delocalized electrons and is slippery due to its atoms being able to slide over one another.
Read more about Graphite here brainly.com/question/27860158
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