What's the problem ? Hardness is not the definition of a metal.
You need to expand your thinking. EVERY element is solid, liquid, and gas, over different ranges of temperature ... including all of the metals. There are only TWO elements that are liquid AT ROOM TEMPERATURE, and mercury is one of them. But on a mild day at the south pole, mercury is solid too.
        
             
        
        
        
The more acidic the substance is, the more the iron nails will corrode (this obviously depends on what your experiment is but hope this helped in some way)
        
             
        
        
        
No. insertions add a nucleotide, deletions delete a nucleotide sequence.
        
                    
             
        
        
        
The initial momentum of the boy is 0 kgm/s the right option is A. 0 kgm/s.
<h3>What is momentum?</h3>
Momentum can be defined as the product of mass and velocity. The S.I unit of momentum is kgm/s.
The initial momentum of the boy can be calculated using the formula below.
Formula:
Where:
- M = Initial momentum of the boy
 
From the question,
Given:
- M = mass of the boy = 60 kg
 - U = Initial velocity of the boy = 0 m/s (at rest)
 
Substitute these values into equation 1
Hence, The initial momentum of the boy is 0 kgm/s the right option is A. 0 kgm/s.
Learn more about momentum here: brainly.com/question/7538238