Answer:
Single replacement reaction (aka single displacement reaction)
Explanation:
In a single replacement reaction, one element is substituted for another in a compound to create a new compound and a new element in the products. The general form is:
A + BC --> B + AC
In the case of this question, Cr and Fe "trade places."
 
        
             
        
        
        
Answer: Avogrado's Constant
Explanation:
One mole of a substance is equal to 6.022 × 10²³ units of that substance (such as atoms, molecules, or ions). The number 6.022 × 10²³ is known as Avogadro's number or Avogadro's constant. The concept of the mole can be used to convert between mass and number of particles. 
 
        
             
        
        
        
<span>A 50 kg student runs up a flight of stairs that is 6 m high. How much work is done? 3000 J. Calculate the work done when a force of 1 N moves a book 2 m. 2 J .... 200 W, 100 W. Calculate the power expended when a 500. N barbell is lifted 2.2 m in 2.0 seconds. 550 W. energy. the property of an object or system that ...</span>
        
             
        
        
        
Hello!
If a reaction occurs when a piece of metal is placed in a solution, you can conclude that the solution is <span>probably acidic because bases rarely react with metals.
Strong Acids, like HCl, react with metals to produce salts and release gaseous hydrogen (H</span>₂) which is evidenced by the generation of bubbles in the solution. The general chemical equation for this kind of reactions for a metal M and an acid HA is:
2M(s) + 2HA(aq) → 2MA(aq) + H₂(g)
Have a nice day!
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