Half-life<span> <span>(abbreviated </span>t</span>1⁄2<span>) is the time required for a quantity to reduce to
half its initial value. The term is commonly used in </span>nuclear
physics<span> <span>to describe how quickly
unstable atoms undergo, or how long stable atoms survive, </span></span>radioactive
decay<span>. since it reduce to half after 4000 years, so the
half life is 4000 years</span>
Answer:
The heat produced by this reaction is 2887J
Explanation:
The reaction of HCl with NaOH occurs as follows:
HCl + NaOH → H2O + NaCl + ΔH
<em>Where ΔH is released heat due the reaction</em>
<em />
The equation of a coffee cup calorimeter is:
Q = C*m*ΔT
<em>Where Q is heat produced, </em>
<em>C is specific heat of the solution (4.18J/g°C), </em>
<em>m is mass of the solution (50mL + 50mL = 100mL = 100g -Because density is 1g/mL) </em>
<em>and ΔT is change in temperature (28.9°C - 22.0°C = 6.9°C)</em>
<em />
Replacing:
Q = 4.184J/g°C*100g*6.9°C
Q = 2887J
The heat produced by this reaction is 2887J
<em />
Chapter
7:
<span>
Chemical Formulas and
Chemical Compounds</span>
We are given with the total mass of fertilizer which is 14.1 oz. This is equivalent to 399.73 grams. 15% of the total is the amount of nitrogen. Thus, the nitrogen amount is 59.96 grams.