We subtract the enthalpies of the reactants from that of the products:

Since this is < 0, this is an exothermic reaction.
Answer:
a. Pb 208
b. About 21.7 minutes
c. only a trace amount
Explanation:
It under goes beta decay.
There should be virtually nothing after an hour
Answer:
THE MASS OF NITROGEN GAS IN THIS CONDITIONS IS 0.0589 g
Explanation:
In an ideal condition
PV = nRT or PV = MRT/ MM where:
M = mass = unknown
MM =molar mass = 28 g/mol
P = pressure = 2 atm
V = volume = 25 mL = 0.025 L
R = gas constant = 0.082 L atm/mol K
T = temperature = 290 K
n = number of moles
The gas in the question is nitrogen gas
Molar mass of nitrogen gas = 14 * 2 = 28 g/mol
Then equating the variables and solving for M, we have
M = PV MM/ RT
M = 2 * 0.025 * 28 / 0.082 * 290
M = 1.4 / 23.78
M = 0.0589 g
The mass of the nitrogen gas at ideal conditions of 2 atm, 25 mL volume and 290 K temperature is 0.0589 g
Atomic mass iron ( Fe ) = 55.84 a.m.u
55.84 g ------------ 6.02x10²³ atoms
24.0 g ------------- ??
24.0 x ( 6.02x10²³) / 55.84
=> 2.58x10²³ atoms
Answer:
the top of the roller coaster
Explanation:
the roller coaster at the top when it has the most potential energy reaches Peak when its going to convert into kinetic energy