Answer:
Sufficient concentration and correct orientation of particles
Explanation:
The collision theory postulates that, for a chemical reaction to occur, there must be collision between reacting particles. 
It implies that the rate of reaction depends on the number of collisions per unit time as well as the fraction that are successful or effective. 
For collisions to be effective, there must be proper orientation of the particles and right concentration of the reactants. 
- The number of effective collisions and rate of reaction are directly proportional to the concentration of of the reactants. 
 
        
                    
             
        
        
        
Answer:
2.05 × 10²³ formula units
Explanation:
Given data:
Mass of AgF =  43.15 g
Number of formula units = ?
Solution:
Number of moles of AgF:
Number of moles = mass/ molar mass
Number of moles = 43.15 g/ 126.87 g/mol
Number of moles = 0.34 mol
Now Number of formula units will be determine by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number
1 mole = 6.022 × 10²³ formula units
0.34 mol × 6.022 × 10²³ formula units
2.05 × 10²³ formula units