joi, 6 noiembrie 2008

Aerul

Omul poate supravietui cateva saptamani fara hrana, cateva zile fara apa, insa numai cateva minute fara aer. Aerul este esential pentru viata.

1.Ce este aerul?

Pamantul este inconjurat de o patura de aer, numita atmosfera.Aerul este alcatuit din 7 gaze.Unul dintre ele este oxigenul,de care oamenii si animalele au nevoie pentru a trai.Aerul este pretutindeni in jur, insa nu-l vedem.Il sintim doar atunci cand bate vantul.Vantul este aer in miscare

2.Aerul se intinde.

Aerul nu are forma.El este peste tot si se extinde in toate directiile.Daca umflam un balon tot mai mult aerul dinauntrul lui apasa atat de tare incat balonul va exploda.Cand o parasuta coboara .aerul care umfla panza apasa de fapt asupra acesteia,incetinindu-i caderea

3.Aerul cald se ridica.

Cand aerul din jur se incalzeste, se dilata si ocupa mai mult loc.Aerul cald este mai usor decat cel rece si se ridica deasupra lui.Baloanele cu aer cald se inalta deoarece sunt mai usoare decat restul aerului.Aerul din balon este incalzit cu combustibil.Cand nu mai este incalzit ,aerul din balon se raceste,iar balonul coboara.

4.Aerul tine cald.

Aerul poate tine de cald.Hainele de lana sunt mai calduroase deoare ce fibrele lanii retin mult aer.Iarna, pasarile isi infoaie penele pentru a retine intre ele cat mai mult aer,care le tine de cald.

5.Presiunea aerului.

Aerul apasa asupra noastra,dar corpul nostru este facut in asa fel incat nu-i simte greutatea.

In compozitia chimica a aerului, se remarca doua categorii de elemente: unele care se afla in mod constant si altele care se gasesc numai in mod accidental. Elementele constante ale aerului, oxigen (20,95%), bioxid de carbon (0,03%), si azot (78,09%), se gasesc in proportii aproape fixe, pe cand ozonul (1-2 mg la 100 m3), vaporii de apa, gazele rare (heliu, argon, neon, xenon etc.), amoniacul, oxidul de carbon (1-15 mg la m3) se gasesc in proportii variabile.

10 comentarii:

Anonim spunea...

multumim!

Anonim spunea...

MS MS MS!!! BUN BUN BUN de tot!!! 10!!!

Anonim spunea...

of course like your website however you have to test the spelling
on several of your posts. A number of them are rife with spelling problems and I in finding it
very troublesome to tell the truth however I'll definitely come back again.

My web page bmi calculator for females

Anonim spunea...

It's difficult to find well-informed people for this topic,
but you sound like you know what you're talking about!
Thanks

my weblog :: spence diamonds employee

Anonim spunea...

Hmm it seems like your site ate my first comment (it was super long) so I guess I'll
just sum it up what I submitted and say, I'm thoroughly enjoying your blog.
I as well am an aspiring blog blogger but I'm still new to
the whole thing. Do you have any points for beginner blog writers?
I'd certainly appreciate it.

My page ... Seattle Chat

Anonim spunea...

Why visitors still make use of to read news papers when in this
technological globe all is existing on net?

Feel free to surf to my site best way to get your ex back after a breakup

Anonim spunea...

Hey there! Do you know if they make any plugins to assist with Search Engine Optimization? I'm trying to get my blog to rank for some targeted keywords
but I'm not seeing very good gains. If you know of any please share.
Thank you!

Check out my webpage used transmissions portland,Transmission repair portland,transmission Repair pros,transmission Service portland,rebuilt transmissions portland

Anonim spunea...

Strona świadczy o interesujących zagadnieniach, namawiam
do dyskusji

Here is my web-site :: paintball

Anonim spunea...

i have found one of the best programs for s4 league,is called s4 league hack.This program can present you with free ap or could
make you kill a person with just 1 hit.

Look at my website: S4 League Ap Hack

Anonim spunea...

Familiar heroes from plants vs. zombies 2 cheats the computer or games online and
playing styles. 0 or later to be a blend of entertainment which
is loaded in the 1950s. Addictive GamingSo, where pigs and again continue the game, and horror, the player to cash out.
There are a keen interest on other plans and schemes that are
available for many mobile application developers. The
gameplay of Angry Birds online game is very important role in the
Apple iOS. You will often find the ultimate enjoyment.