For the first question, the correct answer among the choices listed is option A, a chocolate bar melting in hot car. It is an endothermic process because it absorbs heat energy for it to be melted. For the second question, it think the correct answer is the last option, <span>(-2222) + (-1182) - (-1144).</span>
Answer:
Friction
Explanation:
the resistance that one surface or object encounters when moving over another.
A large unstable nucleus becomes tinier and emits an alpha
particle during Alpha decay. 4/2He or the alpha particle that consists of two
protons and two neutrons can be discharged from the nucleus during the disintegration
of radioactive decay. It has a charge of
positive 2.
Answer: The empirical formula is ![BrF_3](https://tex.z-dn.net/?f=BrF_3)
Explanation:
If percentage are given then we are taking total mass is 100 grams.
So, the mass of each element is equal to the percentage given.
Mass of Br= 58.37 g
Mass of F = (100-58.37) = 41.63 g
Step 1 : convert given masses into moles.
Moles of Br=![\frac{\text{ given mass of Br}}{\text{ molar mass of Br}}= \frac{58.37g}{80g/mole}=0.73moles](https://tex.z-dn.net/?f=%5Cfrac%7B%5Ctext%7B%20given%20mass%20of%20Br%7D%7D%7B%5Ctext%7B%20molar%20mass%20of%20Br%7D%7D%3D%20%5Cfrac%7B58.37g%7D%7B80g%2Fmole%7D%3D0.73moles)
Moles of F =![\frac{\text{ given mass of H}}{\text{ molar mass of H}}= \frac{41.63g}{19g/mole}=2.2moles](https://tex.z-dn.net/?f=%5Cfrac%7B%5Ctext%7B%20given%20mass%20of%20H%7D%7D%7B%5Ctext%7B%20molar%20mass%20of%20H%7D%7D%3D%20%5Cfrac%7B41.63g%7D%7B19g%2Fmole%7D%3D2.2moles)
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For Br = ![\frac{0.73}{0.73}=1](https://tex.z-dn.net/?f=%5Cfrac%7B0.73%7D%7B0.73%7D%3D1)
For F = ![\frac{2.2}{0.7}=3](https://tex.z-dn.net/?f=%5Cfrac%7B2.2%7D%7B0.7%7D%3D3)
The ratio of Br: F= 1 : 3
Hence the empirical formula is ![BrF_3](https://tex.z-dn.net/?f=BrF_3)
Answer:
yes
Explanation:
boiling point, freezing point, ph , density are just a few that would change