Idrk i took chem last year but i didn’t get it
Exothermic. The reaction of the two elements form the compound iron sulfide.
Answer:
is the isotopic notation of the atom
Explanation:
The isotope notation is:

<em>Where a is the mass number = Number of protons + Number of neutrons</em>
<em>b is atomic number = Number of protons</em>
The atomic number define the nature of the atom, the element with atomic number = 15 is phosphorus, P:

a = 15 protons + 16 neutrons = 31
b = 15
is the isotopic notation of the atom.
A statement from the laboratory report which best represents a conclusion for this investigation is that: D. students who spend less time studying after school get lower math grade.
<h3>What is a research?</h3>
A research is also referred to a study and it can be defined as an investigation which typically involves the process of manipulating an independent variable (the cause), in order to determine or measure the dependent variable (the effect) and reach a logical conclusion with results.
<h3>What is an analytical research report?</h3>
An analytical research report can be defined as a well-crafted and written document that is typically used by a researcher to display a detailed analysis of the information which are obtained through a particular research method.
In this scenario, we can infer and logically deduce that a statement from the laboratory report which best represents a conclusion for this investigation is that the group of students who spend less time studying after school would get lower math grade.
Read more on analytical research here: brainly.com/question/17137042
#SPJ1