Answer:
Grinding or breaking an Alka-Seltzer tablet increases the number of particles and increases the surface area. Material which was within the tablet is exposed, allowing for more collisions between reactant particles and resulting in an increased rate of reaction.
Answer:
Phase changes that require a loss in energy are condensation and freezing.
Explanation:
An element’s atomic number is equal to the number of protons in that element’s nucleus. The mass number is the total number of an atom’s protons and neutrons. Protons have a positive charge; electrons have a negative charge; and neutrons are electrically neutral.
Putting it all together, given that the atomic number of lead is 82, the number of protons a lead atom contains is 82. The number of neutrons would be the difference between 207 and 82, or 125 neutrons. Finally, since you have a neutral atom, there must be an equal number of electrons as the number of protons—that is, 82 electrons.
Thus, you’ve got 82 protons, 125 neutrons, and 82 electrons.
There are new ideas and questions that people are trying out and solving. Based off of that, the theories and ideas that we have now will change and evolve with the theories that have been tested and the questions that have been answered.
Answer:
Double replacement reaction
Explanation:
This is what is known as a double replacement reaction. The two parts of each molecule separate and recombine to form two new compounds. For instance, 
separates into 
and 
, while 
separates into 
and 
, and then they recombine with the other compound.
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