Answer:
Strontium is smaller
Strontium has the higher ionization energy 
Strontium has more valence electrons 
Explanation:
It must be understood that both elements belong to the same period i.e the same horizontal band of the periodic table 
While Rubidium is an alkali metal(group 1) while Strontium is an alkali earth metal(group 2)
Since they are in the same period, periodic trends would be useful in evaluating their properties 
In terms of atomic radius, rubidium is larger meaning it has a bigger atomic size 
Generally, across the periodic table, atomic radius is expected to decrease and thus Rubidium which is leftmost is expected to have the higher atomic radius 
Since strontium belongs to group 2 of the periodic table, it has 2 valence electrons which is more than the single valence electron that rubidium which is in group 1 has 
In terms of ionization energy, the atom with the higher number of valence electrons will have the higher ionization energy which is strontium in this case 
 
        
             
        
        
        
Answer:
The error would be $13.
Explanation:
Given data:
Actual payment = $325 
estimated payment = $312
Error = ?
Solution:
Error =  Estimated payment - Actual payment 
Error = $312  -  $325 
Error = -$13
we can discard the negative sign and consider the absolute value. The error would be $13.
 
        
             
        
        
        
Answer : The correct option is C.
Explanation :
Chemical change : It is defined as a change in which a new compounds are formed by the chemical reaction. Changes occurs in their chemical composition and properties.
The molecular structure of a substance changes in a chemical reaction is a chemical change.
- Change in molecular structure means that there is a breaking and formation of bonds in a molecule.
The example of chemical change in terms of change in molecular structure is the reaction of hydrogen with oxygen.
The reaction of hydrogen with oxygen is,

In this reaction, the H-H bond is break and O-H bond is form.
 
        
                    
             
        
        
        
C is a mixture!!!!!!!!!!!!!
        
             
        
        
        
Answer:
I think it will carbon hope it helps