It depends if you are talking about the ones that go up or down
or left and right
the ones that go up and down are called groups
the onesthat go left and right are periods
This problem is providing us with the mass (70 g), absorbed heat (96 J) and initial and final temperatures (293 K and 313 K, respectively) so the specific heat of the material is required and found to be 0.0686 J/(g*K) as shown below:
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Calorimetry:</h3>
In chemistry, we can go over calorimetry by writing the following relationship among heat, mass, specific heat and temperature change:

Thus, one can get the specific heat by solving for C in the previous equation:

Hence, we can plug in the given data to obtain:

Learn more about calorimetry: brainly.com/question/1407669
For radioactive decay, we can relate current amount, initial amount, decay constant and time using:
N = No x exp(-λt)
Half-life = ln(2)/λ
λ = ln(2) / 5730
N/No = 80% = 0.8
0.8 = exp( -ln(2)/5730 x t)
t = 1844 years
To balance this equation simply place the coefficient 2 in front of both the iron metal and the iron II oxide FeO.