what in a flask that holds the heat ,in i mean in the glassy part ,?

Question

exp

Answer 1

It has a vacuum between its inner and outer layers so there is no air to conduct heat between the inner and outer layers.

Answer 2

There are 3 elements in the flask that keep warm things warm or cold things cold.

Heat can be transmitted by convection (currents in a liquid or gas), radiation (transmission of heat energy as electromagnetic waves), or conduction (where two bodies touch and heat energy moves from the hotter object to the colder).

The vacuum between the glass walls removes the possibility of heat loss/gain by conduction, since the liquid inside is not in contact with the air, the silvered coating of the glass walls minimises radiation (light surfaces radiate less heat than dark) and the construction of the bottom of the flask plus the lid means that heat cannot be lost through convection currents.

Simple!

Answer 3

It really isn't "the glassy part" that holds the heat in a thermos bottle - it's the construction.

The glass is really two containers - one inside of the other. It is sealed and the partial vacuum between the glass inhibits the heat (or cold) from reaching the outside of the container where it would be lost to the surrounding air.

Much the same principal is now used when manufacturing thermal, double pane windows.

Answer 4

In the UK it was, or is, made by Thermos and called a Thermos Flask.
The thin metal outer covering protects the inner double walled glass tube.
With the air between the two shells extracted the heat loss is slowed down for several hours. The greater the distance between the two glass containers, the longer the flask will keep its heat.

Answer 5

Most flasks, contain an inner mirror glass, cold or hot liquid is put into the flask and the seal is put in place thus causing a vacuum to hold in suspension the liquid. Providing the seal is good and tight and no air is allowed to enter, the liquid could remain hot/cold for 12hrs. If you remove the bottom of the flask you can see at a glance the suspension by vacuum.

Answer 6

The vacuum surrounding the glass tube prevents the transfer of heat so that fluid in side will remain hot for a long time. Because the thermos does not have a perfect vacuum the fluid will eventually turn cold. The heat loss will be made through the top or lid.

Answer 7

I think the clue is that they're also called vacuum flasks.

There's a small vacuum that doesn't conduct heat between the glassy bits and that means the temperature within changes only very slowly

Answer 8

I think it's the air between the glassy part and the outer part that holds the heat. :)

Answer 9

it's the vacuum between the glass and the outer part of the flash, no air circulates and therefore nothing can take away the heat or cold

Answer 10

its the vacume that holds the heat in, since the heat can only pass the vacum by radiation and unless your drinks are radioactive you will not have any radiation to worry about, that is what keeps the heat in!