Answer:
see note under explanation
Explanation:
When describing system and surroundings the system is typically defined as the 'object of interest' being studied and surroundings 'everything else'. In thermodynamics heat flow is typically defined as endothermic or exothermic. However, one should realize that the terms endothermic and exothermic are in reference to the 'system' or object of interest being studied. For example if heat is transferred from a warm object to a cooler object it is imperative that the system be defined 1st. So, with that, assume the system is a warm metal cylinder being added into cooler water. When describing heat flow then the process is exothermic with respect to the metal cylinder (the system) but endothermic to the water and surroundings (everything else).
Answer:
physical change because even though gas formation was observed the water was undergoing a state change which means that it's original properties are preserved
Answer:
<h3>The answer is 7.50 g/mL</h3>
Explanation:
The density of a substance can be found by using the formula

From the question
mass of iron = 150 g
volume = 20 mL
We have

We have the final answer as
<h3>7.50 g/mL</h3>
Hope this helps you
Sodium Chloride is a compound.