Answer:
10.8 days (3 sig.figs.)
Explanation:
All radioactive decay is 1st order decay defined by the expression A = A₀e^-kt
which is solved for time of decay (t) => t = ln(A/A₀) / -k
A = final weight = 1.0 gram
A₀ = initial weight = 16.0 grams
k = rate constant = 0.693/t(1/2) = 0.693/2.69 days = 0.258 days⁻¹
t = ln(1/16) / -0.258da⁻¹ = (-2.77/-0.258) days = 10.74646792 days (calculator)
≅ 10 days (1 sig. fig. based on given 1 gram mass)
Explanation:
Energy makes molecules in the air move faster and expand, decreasing density. The opposite is true for cold air. Molecules are closer together, and absorb less energy.
Answer:
(V) 1s 2 2s 2 2p 6 3s 2 3p 5
Explanation:
Electron Affinity can be defined as the energy associated with a neutral atom, when an electron is added to form a negative ion.
1s 2 2s 2 2p 6 3s 2 3p 5 , is the electronic configuration of Chlorine.
The electron affinity is positive because it is an exorthermic reaction, meaning that, energy was released during the addition of an electron to the atom.
Cl (g) + e- -------> Cl- (g) = -349KJ/mol
The mass in a chemical reaction remains (mostly) the same.
(except for radiation/nuclear fission, in which mass gets converted into energy)
