**Answer:a**

**Explanation:**

Given

and

Also

therefore

Thus

and

As the pH is less than 7 therefore solution is acidic

**Answer:**

**Explanation:**

opposite charges attract

same charges repel

neutral charges don't attract or repel

**Answer:**

The maximum kinetic energy of the electrons emitted from the surface will be greater.

**Option 3 is correct.**

**Explanation:**

**Given that,**

Wavelength

Wavelength

**We need to calculate the energy for first wavelength**

**Using formula of energy **

Put the value into the formula

**We need to calculate the energy for second wavelength**

**Put the value into the formula**

So, E₂>E₁

**Hence, The maximum kinetic energy of the electrons emitted from the surface will be greater.**

**Answer:**

A dot that represents the box

A vector labeled Fg pointing straight down

A vector labeled Fs, pointing parallel to and up the ramp

**Explanation:**