The best and most correct answer among the choices provided by your question is the first choice or letter A "<span>The chemical bonds of the products have more energy than the chemical bonds of the reactants."
</span>
The term endothermic<span> process describes a process or </span>reaction<span> in which the system absorbs energy from its surroundings; usually, but not always, in the form of heat.</span>
I hope my answer has come to your help. Thank you for posting your question here in Brainly. We hope to answer more of your questions and inquiries soon. Have a nice day ahead!
A single-displacement reaction, also known as asingle-replacement reaction, is a type of chemicalreaction<span> where an element reacts with a compound and takes the place of another element in that compound. This type of </span>reaction<span> is typically pictured like this: Here, A replaces B in the compound BC.</span>
The empirical formula : MnO₂.
<h3>Further explanation</h3>
Given
632mg of manganese(Mn) = 0.632 g
368mg of oxygen(O) = 0.368 g
M Mn = 55
M O = 16
Required
The empirical formula
Solution
You didn't include the pictures, but the steps for finding the empirical formula are generally the same
- Find mol(mass : atomic mass)
Mn : 0.632 : 55 = 0.0115
O : 0.368 : 16 =0.023
- Divide by the smallest mol(Mn=0.0115)
Mn : O =

The empirical formula : MnO₂
The units of ppm means parts per million. Also, It is equivalent to milligrams per liter. It is one way of expressing concentration of a substance. It u<span>sually used to describe the concentration of something in water or soil. We calculate the mass of CaCO3 as follows:
Mass = 75 mg/L (.050 L) = <span>3.75 mg CaCO3</span></span>
Answer:
Final temperature = 
Explanation:
Given that,
Heat added, Q = 250 J
Mass, m = 30 g
Initial temperature, T₁ = 22°C
The Specific heat of Cu= 0.387 J/g °C
We know that, heat added due to the change in temperature is given by :

Put all the values,

So, the final temperature is equal to
.