Answer: 2. Density
3. Physical Property
4. Chemical Change
5. states of matter
Explanation: Density is referred as mass per unit volume. Physical properties are observable characteristics of an object. An new formation of a substance in a chemical reaction is a chemical change. And solids, liquids, and gases are states of matter.
Answer: A, B, D
Explanation:
all of these examples show matter moving from a high volume of matter, to low volume of matter. When the molecules of the paint, toast, and chemicals were released, they will try to disperse away from the high concentration
Answer:
Mendeleev left spaces in his periodic table because he predicted there were elements that weren't discovered yet that would fit in these spaces.
Explanation:
Answer:
268 nm
Explanation:
The equation needed to find wavelength is:
E = hc / w
In this equation,
-----> E = energy (J)
-----> h = Planck's Constant (6.626 x 10⁻³⁴ J*s)
-----> c = speed of light (3.0 x 10⁸ m/s)
-----> w = wavelength (m)
To find the wavelength, you can plug the given values into the equation and simplify. Then, you can convert meters to nanometers.
E = hc / w
7.41 x 10⁻¹⁹ J = (6.626 x 10⁻³⁴ J*s)(3.0 x 10⁸ m/s) / w <---- Input given values
7.41 x 10⁻¹⁹ J = 1.9878 x 10⁻²⁵ / w <----- Simplify
(7.41 x 10⁻¹⁹ J) x w = 1.9878 x 10⁻²⁵ <----- Rearrange
w = 2.68 x 10⁻⁷ m <----- Simplify
2.68 x 10⁻⁷ m 1 x 10⁹ nm
---------------------- x ---------------------- = 268 nm
1 m
