Answer:
2.00 moles of Ni has 1.2 *10^24 atoms
Explanation:
Step 1: Data given
Number of moles Ni = 2.00 moles
Number of Avogadro = 6.022*10^23 /mol
Step 2: Calculate number of atoms
Number of particles (=atoms) = Number of Avogadro * number of moles
Number of atoms = 6.022 * 10^23 /mol * 2.00 moles
Number of atoms = 1.2*10^24 atoms
2.00 moles of Ni has 1.2 *10^24 atoms
Answer : The mass of the water in two significant figures is, 
Explanation :
In this case the heat given by the hot body is equal to the heat taken by the cold body.


where,
= specific heat of iron metal = 
= specific heat of water = 
= mass of iron metal = 32.3 g
= mass of water = ?
= final temperature of mixture = 
= initial temperature of iron metal = 
= initial temperature of water = 
Now put all the given values in the above formula, we get


Therefore, the mass of the water in two significant figures is, 
Answer:
The answer is all of the above
Explanation:
Sound has waves which are compression waves and those waves transfer into energy molecules. Sound is heard by human ears. Sound waves can behave in predictable ways. All sound requires a medium through to travel