Ask question

Ask question

All categories

2 years ago

8

Scientists excavating at the bottom of the ocean come across fossilized remains of an ancestor of a mountain goat. How can this

be explained?

1 answer:

galina1969 [7]2 years ago

4 0

There was land on that surface before there was water

You might be interested in

Bromine has chemical properties most similar to...

Aleksandr-060686 [28]

Flourine.

You are very welcome

3 0

2 years ago

Read 2 more answers

What is the identity of the atom shown?

Charra [1.4K]

The answer is a , as aluminium has 13 protons and electrons .

6 0

2 years ago

Read 2 more answers

Calculate the maximum KE and velocity of an electron from zinc by a 275nm photon

Dmitry [639]

Answer:

Kinetic energy: $6.024*10^{-20}$

Velocity: $3.64*10^{5}$

Explanation:

From the equations of the photo-electric effect,

We know:

$hv=hv_0+K.E$

Where,

1. $h$ is the Planck's constant which is $6.626*10^{-34}$

2. $v,v_0$ are the frequency of light emitted and threshold frequencies respectively.

3. $K.E$ is the kinetic energy of the electrons emitted.

By fact, we come to know that the threshold frequency of Zn is 300nm

And also $v=\frac{c}{d}$

Where ,

1. $c$ is the speed of light $=3*10^8$

2. $d$ is the wavelength.

Thus,

$\frac{hc}{d}=\frac{hc}{d_0}+K.E\\K.E=\frac{hc}{d}-\frac{hc}{d_0}\\K.E=hc*(\frac{1}{d}-\frac{1}{d_0})\\K.E=6.626*10^{-34}*3*10^8*(\frac{1}{275*10^{-9}}-\frac{1}{300*10^{-9}})\\K.E=6.024*10^{-20}kgm^2s^{-2}$

Now to find velocity:

$K.E=\frac{1}{2}mv^2\\v^2=1.324*10^{11}\\v=3.64*10^5$

8 0

3 years ago

Perform the following calculations and then determine the correct answer following the significant figure rules: 8.7 g + 15.43 g

Sidana [21]

43.13 g is the answer

5 0

2 years ago

Which statement below correctly describes what changes when moving downwards from fluorine to chlorine on the periodic table?

BlackZzzverrR [31]

D to do it for a while but it was

6 0

2 years ago