Answer:
I believe the answer is A
Explanation:
Work and energy are related because when you work, you cause displacement in the object you are exerting upon. While this happens, you transfer energy between the systems. Both work and energy share the same SI unit, called the joule.
1. A filter was used to separate the sand from the salt water solution (The process of decanting was used if a filer was not available).
2. A Bunsen burner was used to boil away the water from the salt water solution leaving only salt.
I hope this helps. Let me know if anything is unclear.
Answer:
B. Measures of central tendency
Explanation:
Mean, median and mode are best described as measures of central tendency of a given data set.
Mean is the average of the samples given
Mode is the data point with the most frequent occurrence
Median is the data point that lies in the middle
- All these parameters tells us how far a data point is from the middle or how close they are.
Exothermic reactions:
1) release heat to the surroundings
2) the change of enthalpy, ΔH, is negative: ΔH < 0
3) the temperature of the system increases
With that you can conclude about every equation given:
<span>NH3(g) + 12.0 kcal → ½N2(g) + 3/2 H2(g) : is not exothermic because heat in the side of the reactants means that heat is being used, not released.
C(graphite) → C(diamond), ΔH = - 0.45 kcal : is exothermic because ΔH is negative
C + 2S → CS2, ΔH = 27,550 cal: is not exothermic because ΔH is positive
CH4 + 2O2 → CO2 + 2H2O + 212,800 cal : is exothermic because heat appears as a product of the reaction, which means that it is released.
2H2O → 2H2 + O2, ΔH = +58 kcal : is not exothermic because ΔH is positive.</span>
