Answer:
 electrons
  electrons
Explanation:
The total charge Q is the sum of the charge of the N electrons contained in the sphere:

 charge of a electron
    charge of a electron 
We solve to find N:

 
        
             
        
        
        
Answer:
- Increases levels of well-being neurotransmitters
- Improves fitness
- Improves mental health
- Reduces the risk of developing diseases
Explanation:
Performing physical activities helps to build a healthy relationship with yourself, in the sense that physical activity promotes health at all levels. Health is a set of physical, mental and social well-being, so physical activity reaches all these levels and increases the quality of life for a person as a whole.
There are several types of physical activities that can be performed and you can choose the one that best fits your preferences and routine. A walk for example can be done in any safe place and at any time and it already helps in improving physical conditioning, in receiving serotonin and endorphins, in reducing blood pressure and protecting the heart and in improving mental health.
So the ideal is for each person to set their own goals in relation to their health and seek to achieve them, either to have a better quality of life, to socialize more with people, to prevent diseases, etc.
 
        
             
        
        
        
A screw driver rusting when left in a pail of water is a chemical reaction
        
                    
             
        
        
        
Answer:
- Alarm Clock. The buzzing sound of an alarm clock helps you wake up in the morning as per your schedule. The sound is something that you can’t see, but hear or experience.
-  Cell Phones Cellphones have become like Oxygen gas in modern social life. Hardly, anyone would have been untouched by the effects of a cell phone. Whether conveying any urgent message or doing incessant gossips, cellphones are everywhere. But do you know how does a cell phone work? It works on the principle of electricity and the electromagnetic spectrum, undulating patterns of electricity and magnetism.
- Walking.Now, when you get ready for your office/school, whatever medium of commutation is, you certainly have to walk up to a certain distance. You can easily walk is just because of Physics. While you have a walk in a park or on a tar road, you have a good grip without slipping because of a sort of roughness or resistance between the soles of your shoes and the surface of the road.
Explanation:
physical is related to things perceived through the senses as opposed to the mind; tangible or concrete.
 
        
             
        
        
        
Answer:
A
Explanation:
because thats what I put and got it right