Answer: If a hydrogen atom and a helium atom have the same kinetic energy then the wavelength of the hydrogen atom will be roughly equal to the wavelength of the helium atom.
Explanation:
The relation between energy and wavelength is as follows.

This means that energy is inversely proportional to wavelength.
As it is given that energy of a hydrogen atom and a helium atom is same.
Let us assume that  . Hence, relation between their wavelengths will be calculated as follows.
. Hence, relation between their wavelengths will be calculated as follows.
 ... (1)
    ... (1)
 ... (2)
         ... (2)
Equating the equations (1) and (2) as follows.

Thus, we can conclude that if a hydrogen atom and a helium atom have the same kinetic energy then the wavelength of the hydrogen atom will be roughly equal to the wavelength of the helium atom.
 
        
             
        
        
        
Answer:
1 mole of platinum 
Explanation:
To obtain the number of mole(s) of platinum present, we need to determine the empirical formula for the compound. 
The empirical formula for the compound can be obtained as follow:
Platinum (Pt) = 117.4 g
Carbon (C) = 28.91 g
Nitrogen (N) = 33.71 g
Divide by their molar mass 
Pt = 117.4 / 195 = 0.602
C = 28.91 / 12 = 2.409
N = 33.71 / 14 = 2.408
Divide by the smallest 
Pt = 0.602 / 0.602 = 1
C = 2.409 / 0.602 = 4
N = 2.408 / 0.602 = 4
The empirical formula for the compound is PtC₄N₄ => Pt(CN)₄
From the formula of the compound (i.e Pt(CN)₄), we can see clearly that the compound contains 1 mole of platinum. 
 
        
             
        
        
        
Answer:
A
Explanation:
It is formed after the star has ended its star cycle into a supernova. The star collapsed into a neutron star that is smaller than the progenitor star but has inherited angular momentum. IT, therefore, spins faster emitting electromagnetic radiation that seems to pulsate.
 
        
                    
             
        
        
        
Tell the teacher, do NOT clean it up yourself.
 
        
             
        
        
        
Answer: dilute 
Explanation:
A concentrated solution which is used to prepare solutions of lower concentrations by diluting it with addition of water.
A dilute solution is one which contains lower concentration.
Using Molarity equation:
 =concentration of stock solution = 0.150 mol/L
 =concentration of stock solution = 0.150 mol/L
 = volume of stock solution = 10.0 ml
 = volume of stock solution = 10.0 ml
 = concentration of dilute solution = ?
 = concentration of dilute solution = ?
 = volume of dilute solution = (10.0+90.0) ml = 100.0 ml
 = volume of dilute solution = (10.0+90.0) ml = 100.0 ml


As the concentration is less than the original concentration, the solution is termed as dilute.