yes substances Do react by mass
The answer should be B: -3
An acid has a pH <7. 7 is the pH of a neutral substance, like water, and substance with a pH >7 are considered basic or alkaline.
Answer:
713 nm. It is not visible with the naked eye.
Explanation:
Step 1: Given data
- Energy of light (E): 2.79 × 10⁻¹⁹ J
- Planck's constant (h): 6.63 × 10⁻³⁴ J.s
- Speed of light (c): 3.00 × 10⁸ m/s
Step 2: Calculate the wavelength of the light
We will use the Planck-Einstein equation.
E = h × c / λ
λ = h × c / E
λ = 6.63 × 10⁻³⁴ J.s × 3.00 × 10⁸ m/s / 2.79 × 10⁻¹⁹ J
λ = 7.13 × 10⁻⁷ m
Step 3: Convert "λ" to nm
We will use the relationship 1 m = 10⁹ nm.
7.13 × 10⁻⁷ m × (10⁹ nm/1 m) = 713 nm
This light is not in the 400-700 nm interval so it is not visible with the naked eye.
It’s sulfur because it shows little reactivity.
