Anonymous
Anonymous asked in Science & MathematicsChemistry · 4 months ago

# EASY true/false Chemistry question, WILL AWARD BEST ANSWER. THANK U!!!?

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• 4 months ago

E=mc² .......... I'll assume that is the equation

The equation shows an EQUIVALENCY between mass and energy. A certain energy is equivalent to a certain mass. The c² is a conversion factor. The equation doesn't say that matter turns into energy. The bottom line is that mass and energy are manifestations of the same thing, but their measurements are expressed in different units. One must be careful and not substitute "matter" for "mass."

1. A change in mass is related to a change in energy -- no. If what is meant is that as one goes up, the other must go down. Mass and energy can't change is they are equivalent.

2. Matter can change form during a chemical reaction -- yes. But that has nothing to do with Einstein's equation.

3. Energy and mass are the same -- yes. If this means that mass and energy are equivalent, then that is what Einstein's equation says, but they are not the same numerically, because mass and energy are usually expressed in different units. That's what the c² takes care of. (c=3.00x10^8 m/s)

... 1.00 kg x (3.00x10^8 m/s)² = 9.00x10^16 kgm²/s² = 9.00x10^16 J

... 1 J = 1 kgm²/s²

4. Particles moving at the speed of light have a certain amount of energy -- no. This one is particularly laughable because particles won't be moving at the speed of light. Of course, anything moving has kinetic energy, but the speed of light is the speed limit of the universe. Particles can approach the speed of light but not attain it. As particles get closer to the speed of light (increasing kinetic energy) their masses increases (there's E = mc²) again. Should they hypothetically reach the speed of light, the mass would be off the chart, so to speak. But as their mass increases more and more work must be done to accelerate them. This is why the speed of light could be asymptotically approached, but not reached, and even at that, only atom-sized particles can get anywhere close.

• Dr W
Lv 7
4 months ago

.. a change in mass is related to a change in energy... TRUE.. if all else is equal

.. matter does change during chemical reactions.. TRUE.. but matter doesn't change

.. .. .. .into energy during ordinary chemical reactions anyway.. regardless of that equation

.. .. ... ordinary chemical reactions involve the rearrangement of ELECTRONS.

.. .. .. .the E = mc² refers to NUCLEAR events

.. energy and mass are the same thing.. not exactly but they are different ways of

.. . .. ..looking at the same thing.. mass-energy

.. particles moving at the speed of light.. etc.. particles cannot move at the speed of light

.. . . ... so this is FALSE.

so the first 3 are possible choices that could be argued as TRUE and the last is FALSE

**********

let's think about a very simple conceptual analogy...

Image a traffic cone.. without the square base at the bottom.. just the cone part... with

.. radius at the base = r

.. height = h

If you look at it from the side, you see a triangle

if you look at it from the bottom, you see a circle

The area of the circle...let's call it Ac.. .goes by Ac = π*r²

The area of the triangle = At = ½ base * height = ½ * 2r * h = r * h

we know the Volume of a cone = Vc = ⅓ * π * r² * h

so we can do this

.. Vc = ⅓ * r² * h = ⅓ * r * π * (r * h) = ⅓ * r * π * At

and we can do this

.. Vc = ⅓ * π * r² * h = ⅓ * h * (π * r²) = ⅓ * h * Ac

.. ⅓ * r * π * At = Vc = ⅓ * h * Ac

or

.. ⅓ * r * π * At = ⅓ * h * Ac

which simplifies to.

.. r * π * At = h * Ac

rearranging

.. At = Ac * (h / r * π)

if we say for all "similar cones".. h/r is a constant.. then we can write

.. At = Ac * k

and we have an equation relating the area of the circle to the area of the triangle... for similar cones. Does that mean circles and triangles are the same thing? NO. Does it mean I can convert from 1 to the other? No. But it does mean I can change my viewpoint from one to the other by applying "k".

More importantly it means there is a 3D cone that I'm applying 2D viewpoints and math to it.

Mass-Energy is the same thing. 1 entity and we're observing it from different viewpoints of lower dimensions that are related by a constant.. c²

*********

So I'd probably go with the choice #1 and argue this

choice #2 suggests ordinary chemical reactions.. although the involve a change in energy, that change is related to the change in electrostatic forces as electrons are rearranged not mass lost or gained

choice #3 suggests mass and energy are identical.. it should really say.. they are different views of the same thing.. mass-energy.

• 4 months ago

The first option is true.

The third option is false.

The second and fourth options are true, but Einstein's equation says nothing about them.

• alan P
Lv 7
4 months ago

The equation E=mc^2 is saying, using consistent units, that the energy produced by converting matter into energy is equal to the mass of the matter multiplied by the speed of light squared. I think the third answer is closest.

• alan P
Lv 7
4 months agoReport

Maybe I'm not using strictly the right words but isn't that how nuclear power works. In laymans terms some matter diasppears and becomes energy