a substance dissolves.
like adding a soluble salt to water, it just dissolves, i.e dissociates homogeneously as water is able to dissociate salts (ionic compounds) into its ions. (it can also dissociate other non-ionic compounds like HCL)
the salt still remains chemically as a salt and is unchanged chemically thus it is not an indication of a chemical reaction as no chemical reaction has taken place.
the formation of a precipitate is a chemical reaction because a new substance (i.e new chemical) is formed. For example adding aqueous sodium hydroxide into an aqueous solution with CU2+ cations will form a blue precipitate (that is copper (II) hydroxide which is insoluble, hence it precipitates). Since a new chemical is formed, a chemical reaction has taken place and thus indicates a chemical reaction.
color change... im not sure but usually a color change will only occur when a new substance is formed. Like iron corrodes (i.e rust) slowly in moist air to form hydrated iron (III) oxide that is rust. (brown color).
usually adding a mixture to a mixture has little energy change, i.e little heat taken in by the reaction mixture or little heat given out by the reaction mixture. Whereas when a new substance is formed, there is usually noticeable energy change like the container gets colder or hotter (without heat being supplied of course). For example dissolving basic oxides into water releases energy ( more energy released than gained = exothermic reaction).
i think that should be the answer... hope it helped :D
Explanation:
The attached figure shows data for the cart speed, distance and time.
For low fan speed,
Distance, d = 500 cm
Time, t = 7.4 s
Average velocity,
Acceleration,
For medium fan speed,
Distance, d = 500 cm
Time, t = 6.4 s
Average velocity,
Acceleration,
For high fan speed,
Distance, d = 500 cm
Time, t = 5.6 s
Average velocity,
Acceleration,
Hence, this is the required solution.
<span>the statement that is true regarding flexibility is : b. a joint's range of motion will be lost if the joint is not used regularly.
Our body is like a machine. If we not constantly heat it up, our body will be more prone to injury. We can see that the old people who lived within the tribe in the middle of the mountain are far stronger than the one who lived in the city.</span>
Answer:
In bringing you to a halt, the sand and the water exert the same impulse on you, but the sand exerts a greater average force
Explanation:
Answer:
B. - 0.328
Explanation
Potential Energy:<em> This is the energy of a body due to position.</em>
<em>The S.I unit of potential energy is Joules (J).</em>
<em>It can be expressed mathematically as</em>
<em>Ep = mgh........................... Equation 1</em>
<em>Where Ep = potential energy, m = mass of the coin, h = height, g = acceleration due to gravity,</em>
<em>Given: m = 2.74 g = 0.00274 kg, h = 12.2 m, g = 9.8 m/s²</em>
Substituting these values into equation 1
Ep = 0.00274×12.2×9.8
Ep = 0.328 J.
Note: Since the potential energy at the surface is zero, the potential Energy with respect to the surface = -0.328 J
The right option is B. - 0.328
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