<span>The part of making a solution that always releases energy is the overall change in forming the solution. The answer is letter D. Although letters A, B and C can be viable answers but, it is not always the case. There are some substances that when you mix or separate them requires more energy or less energy. An example would be w</span>hen the formation (or enthalpy of formation) of carbon
dioxide is negative, it means that it releases heat to the surroundings. When
it releases heat to the surroundings, the reaction is exothermic. Another example is when you mix baking soda and muriatic acid, the resulting mixture is colder. When it is cold, it means that the reaction is endothermic. So the best answer is letter D.
Any change in which the composition of material does not change that is it retains its identity but changes its state or form is known as a physical change.
The properties of metal to draw them into wires is known as ductility. When a copper is drawn into wire the only change that occurs is change in its shape and size no change will take place into its composition that is the wires are still possessing the properties of copper metal. Thus, a physical change takes place when copper is drawn into wire.
C. You should ALWAYS ask the teacher if you don't get something; your friends could be wrong, don't guess it, and NEVER cheat. Hope this helps!!
Adopting the number of avogrado 6.02 * 10²³ / mol
<span>Sodium chloride (table salt)</span> Molar Mass = 58.44 g / mol
We will first have to find the number of moles in 35 grams of the element, like this:
1 mol ----------------- 58.44 g
X ---------------------- 35 g
58.44 * x = 35 * 1
58.44x = 35

X = 0.598904...
X ≈ 0.60<span> mol </span>
Now we will find how many atoms there are in 0.60 mol of this element, like this:
1 mol -------------------- 6.02 * 10²³ atoms
0.60 mol ----------------- X
X = 0.60 * 6.02 * 10²³
Temperature change, colour change, releasing gas, bubbles and change in odor