This means that the steel bar lost 14900 j of thermal energy. what is the change in temperature of the steel bar? recall that the steel decreases in temperature, and use the value of 0.49 j/g•°c as the specific heat capacity of steel. the video shows the mass of the steel to be 40.7 g.

Explanation:

Hello,

In this case, the heat is related with the change in the temperature via the heat capacity and the involved mass as shown below:

Now, as it is stated that there is an amount of lost heat, such value turn out negative implying that the final temperature is lower than the initial one, in such a way, one computes as a measure of the change in the temperature as follows:

Best regards.

answer: enthalpy

explanation:

for a exothermic reaction, the energy is released i.e. the energy of the products is lower than the energy of the reactants.

= enthaply

= energy of products

= energy of reactants

as , thus comes out to be negative. negative value of enthalpy shows that the reaction is exothermic.

14 days is the half-life of phosphorus-32