I believe the correct answer from the choices listed above is option D. Catalysts lower the activation energy of a chemical reaction. It <span>is a substance which speeds up a reaction, but is chemically unchanged at the end of the reaction. It provides another pathway for the reaction to occur.</span>
It is a covalent compound
When an object/liquid/food etc contains hot energy, the heat particles are moving around causing the heat. 8ounces of soup would cool off faster, because there is less liquid for the heat particles to be in, there for less heat particles, therefore cooling off faster. Pls give Brainliest, and good luck!
Answer:
15 h
Explanation:
Okay, the first thing that we all have to know before we can answer this question is that this Topic that is, Chemistry of Radioactivity is related to kinetics in a way that Radioactive disintegration follows the first order of Reaction which is under kinetics. So, we will be using the first order kinetics rate law to answer this question. Using the equation (1) below;
k =[ 2.303/ t ]×log ([N°}/ [Nr]) --------(1).
We are given from the question that N° = initial sample = 0.8 mg and Nr= sample remaining = 0.2 and the time taken = t= 30.0 h.
k= (2.303/ 30.0 h ) × log (0.8/0.2).
k=0.076768 h^-1 × log (4).
k= 0.076768 h^-1 × 0.6021.
k= 0.0462 h^-1.
Therefore, using the formula for Calculating half life below for first order kinetics we will be able to find out answer.
k = ln 2/ t(1/2). Where t(1/2) is the half life.
t(1/2) = ln 2/ k.
t(1/2) = ln 2 / 0.0462 h^-1.
t(1/2)= 0.6931/0.0462 h^-1.
t(1/2)=15 h