HCl + NaOH -> H2O + NaCl
CaCO3 + KI -> K2CO2 + CaI2
AlF3 + Mg(NO3)2 -> Al(NO3)3 + MgF2
They lack a cell nucleus.

When an opaque obstacle is placed between a source of light and a screen, a shadow of the obstacle is formed on the screen. The kind of shadow depends on the size of the source of light. In other words, the earth casts its shadow on the moon. The solar eclipse occurs when the moon comes between the sun and the earth.
Answer:
The phase difference between the reflected waves when they meet at the tuning fork is 159.29 rad.
Explanation:
Given that,
Frequency of sound wave = 240 Hz
Distance = 46.0 m
Distance of fork = 14 .0 m
We need to calculate the path difference
Using formula of path difference

Put the value into the formula


We need to calculate the wavelength
Using formula of wavelength

Put the value into the formula


We need to calculate the phase difference
Using formula of the phase difference

Put the value into the formula



Hence, The phase difference between the reflected waves when they meet at the tuning fork is 159.29 rad.