C. The mass number is the amount of Protons and electrons there are combined, so 200 - 80 is 120.
Answer:
1) The volume occupied by an atom is composed of mainly empty space
2) Atoms have a very small, relatively dense, central nucleus that is positively charged
3) The region around the nucleus of an atom are orbited by negatively charged electrons in a the same fashion planets orbit around the Sun.
Explanation:
The selection of gold for the gold foil experiment was due to its ability to be rolled into extremely thin sheets such that it was expected for alpha particle to perforate or pass through the foil.
Answer:
T2 = 135.1°C
Explanation:
Given data:
Mass of water = 96 g
Initial temperature = 113°C
Final temperature = ?
Amount of energy transfer = 1.9 Kj (1.9×1000 = 1900 j)
Specific heat capacity of aluminium = 0.897 j/g.°C
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = T2 - T1
Now we will put the values in formula.
Q = m.c. ΔT
1900 j = 96 g × 0.897 j/g.°C × T2 - 113°C
1900 j = 86.112 j/°C × T2 - 113°C
1900 j / 86.112 j/°C = T2 - 113°C
22.1°C + 113°C = T2
T2 = 135.1°C
The molar mass of potassium chloride is 74.5513g/mol, and the molar mass of potassium bromide is 119.002g/mol. You first need to find how many moles are in the given sample, so you divide the mass by the molar mass of potassium bromide. You don’t necessarily need to convert the mole ratio, since both the potassium chloride and potassium bromide have 2 moles in the chemical equation. Lastly, you multiply the moles at this point by the molar mass of potassium chloride, and you get your final answer.
Answer: 222.91g KCl
