Answer:
1. A substance that can be separated into two or more substances only by a chemical change is a(n) _____.
solution
element
mixture
compound
2.
Which of the following materials is a substance?
air
gasoline
stainless steel
silver
3.
The first figure in a properly written chemical symbol always is _____.
boldfaced
capitalized
italicized
underlined
4.
Which of the following represents a compound?
H
H-3
H2O
O-16
5. What do chemical symbols and formulas represent, respectively?
elements and compounds
atoms and mixtures
compounds and mixtures
elements and ions
Explanation:
Answer:
When you use your control remote, you can see that there is not a "material" thing that comes out of the control remote and goes to the TV, but there is actually energy that comes from the control remote (and this is why your control remote needs battery)
This energy is called an "electromagnetic wave" usually in the infrared range, this means that the energy that comes from the control remote has less energy than the visible red light (and this is why we can not see the light that comes out of the control remote), and this "signal" is read by the TV, in order to change of channel or change the volume.
You even can see that there is a sort of light (electromagnetic wave) coming out from it if you point with a camera to the small bulb that is in the front of the control remote.
<span>that statement is true.
In walking process, we need the force of friction so our feet could pushed back agains the ground. Without the force of friction it would be really hard to stand. And even we could stand, we will be sliding all over the place when we try to walk.</span>
Answer:0.8 meter
Explanation:
Frequency=426.7hz
Velocity=346m/s
Length =velocity ➗ frequency
Length=346 ➗ 426.7
Length =0.8
