D. A set of steps that help scientists gather knowledge
Answer: The correct option is 1.
Explanation: Endothermic reactions are the reactions in which heat is provided to break down the reactant molecules.
In option 1:
The stronger intermolecular forces between the particles in solid molecule are broken down to convert into gaseous form. Hence, some energy in the form of heat is provided to move them far apart. Therefore, it is considered as an endothermic reaction.
In option 2, 3 and 4:
All the other processes involves the formation of bonds and thus there is no need to provide any energy.
Density = mass/volume
From this equation we can also say:
Volume = mass/density
V = 2500.0g/10.5g/cm3
V = 238 cm3
Answer: velocity
Explanation: trust me man
