Biology; Chemistry; Physics: Post your doubts here!

[raynalist]

thanks a lot

 

[raynalist]

thanks a lot

 

[raynalist]

hi plz can u explain me about radioactive decay of alpha beta and gamma particles

 

[Zuhsid]

thanks a lot

Any time bro!!!

 

[Zuhsid]

hi plz can u explain me about radioactive decay of alpha beta and gamma particles

What do you wanna know about it??
The properties of the particles?
Why and how they decay?
How are they detected?
Nuclear fission/fusion?

 

[raynalist]

in brief only.Their properties and how they decay

 

[Zuhsid]

in brief only.Their properties and how they decay

Alpha:

• Weight: 4 times the weight of a hydrogen atom / 8000 times more massive than Beta particles

• Ionization: Causes intense ionization

• Penetration: Able to penetrate only 5cm of air (safe distance:10-20cm in air), easily absorbed by thin sheet of aluminum or thick sheet of paper

• Nature of radiation: They are the positive nucleus of Helium

• Charge: +

• Nuclear Equation(how formed): When alpha decay occurs a group of two protons and two neutrons (helium nucleus) comes out of the nucleus. Therefore the proton number decreases by 2 but the nucleon number decreases by 4. The resulting daughter nucleus is of an element 2 positions to the left of the 'parent' in the periodic table.

http://physicsnet.co.uk/wp-content/uploads/2010/05/alpha-decay-equation.jpg

• Speed: 0.1 times the speed of light / 30000000 m/s
• Deflection: Being heavier, they are not deflected easily(but do deflect)

Beta:

• Weight: 1/1840 of a hydrogen atom(mass of an electron
• Ionization: Cause some ionization because of less mass
• Penetration: Able to penetrate 1m of air or 3mm thick Aluminum sheet (Safe to have 1cm of Aluminum sheet between source and person)
• Nature of radiation: Fast moving electrons
• Charge: -
• Nuclear Equation(how formed): When beta decay occurs a neutron within the nucleus emits the particle and changes into a proton. Therefore the proton number increases but the nucleon number stays the same (only now you have one more proton and one less neutron!). The resulting daughter nucleus is of an element 1 position to the right.
  http://physicsnet.co.uk/wp-content/uploads/2010/05/beta-particle-equation.jpg
• Speed: 0.99 of the speed of light
• Defection: Being high in charge( and less mass), they are deflected easily.

Gamma:

• Weight: No physical mass (thats why hey are rays, not particles)
• Ionization: Cause little ionization because no physical mass
• Penetration: Very penetrating, can pass through few mm of lead sheet. Must be stored in thick lead containers
• Nature of radiation: Electromagnetic Radiation
• Charge: No charge(neutral), as electromagnetic waves
• Nuclear equation(how formed): Sometimes, after its emission of an alpha, beta particle, the nucleus is still in an excited state, called a metastable state. In order to get to a lower energy state it emits a quantum of energy in the form of a gamma ray. No matter is emitted from the nucleus therefore the nucleon number and the proton number remain the same. Before and after emission of the gamma ray they are the same isotope of the element.
• Speed:Speed of light
• Deflection: Being neutral in charge, they are not deflected at all.

All 3 radiation come from unstable nuclei of an element like uranium, plutonium, radium etc...
Radiation occurs randomly over space and time!!!

 

[shaysharyf]

So, I'm new here, and I have this question to ask.
Explain the difference between excretion and egestion. (3 marks).
What's worrying me is the marks. Will I get the full marks just by writing the definitions of both?

Thanks in advance.

 

[Aly Emran]

So, I'm new here, and I have this question to ask.
Explain the difference between excretion and egestion. (3 marks).
What's worrying me is the marks. Will I get the full marks just by writing the definitions of both?

Thanks in advance.

no u wont get full marks writing their definations. u have to write both definations and prove with examples

 

[shaysharyf]

Thank you.

 

[Zuhsid]

no u wont get full marks writing their definations. u have to write both definations and prove with examples

Before the exam, do go through the list of command words, like explain and describe etc..... They tell you what to write with each command word!!!
You can find them at the start of your redspot past papers...

 

[Aly Emran]

Before the exam, do go through the list of command words, like explain and describe etc..... They tell you what to write with each command word!!!
You can find them at the start of your redspot past papers...

it shaysharyf who needs advice im done with it

 

[shaysharyf]

it shaysharyf who needs advice im done with it

Haha, true. and thanks Zuhsid.

 

[Zuhsid]

it shaysharyf who needs advice im done with it

lol... i know.... must've pressed reply on the wrong comment!!

 

[Aly Emran]

lol... i know.... must've pressed reply on the wrong comment!!

haha no prob

 

[shaysharyf]

Before the exam, do go through the list of command words, like explain and describe etc..... They tell you what to write with each command word!!!
You can find them at the start of your redspot past papers...

I couldnt find those red spot past papers. Help?

 

[shaysharyf]

Before the exam, do go through the list of command words, like explain and describe etc..... They tell you what to write with each command word!!!
You can find them at the start of your redspot past papers...

I couldnt find those red spot past papers. Help?

 

[Zuhsid]

I couldnt find those red spot past papers. Help?

You cant find your redspot past papers or you cant find the list within the book?

 

[shaysharyf]

You cant find your redspot past papers or you cant find the list within the book?

I cant find the list within the book. I have the redspot GCE biology keypoints book (pure).

 

[Zuhsid]

I cant find the list within the book. I have the redspot GCE biology keypoints book (pure).

K... let me see what i can do, then ill tell u!!