Answer:
The correct option is the option;

Explanation:
The wavelength of a wave is the distance between two successive crests of the wave
Therefore, the wavelength, λ, is given by the fraction of the velocity, <em>v</em>, of the wave divided by the frequency, <em>f</em>, (the number of cycles that pass through a point) of the wave
Mathematically, we have;


Answer:
d = 0.98 g/L
Explanation:
Given data:
Density of acetylene = ?
Pressure = 0.910 atm
Temperature = 20°C (20+273 = 293 K)
Solution:
Formula:
PM = dRT
R = general gas constant = 0.0821 atm.L/mol.K
M = molecular mass = 26.04 g/mol
0.910 atm × 26.04 g/mol = d × 0.0821 atm.L/mol.K×293 K
23.7 atm.g/mol = d × 24.1 atm.L/mol
d = 23.7 atm.g/mol / 24.1 atm.L/mol
d = 0.98 g/L
<span>D. The screw changes the direction of a force - it converts linear force into rotational force. It also reduces the force required - the closer the threads, the smaller the input force required to get the same output force.</span>
solution:
You need to find the frequency, and they have already given you the wavelength. And since you already know the speed of light, you can use formula (2) to answer this problem. Remember to convert the nano meters to meters because the speed of light is in meters. 

Answer: The metalloids are a unique group of elements that share properties of both metals and nonmetals.
Explanation: They're also called the semimetals because of the shared properties of these elements along the dividing line between metals and nonmetals.