Boiling is the rapid vaporization of a liquid, which occurs when a liquid is heated to its boiling point, the temperature at which the vapour pressure of the liquid is equal to the pressure exerted on the liquid by the surrounding atmosphere. There are two main types of boiling; nucleate boiling where small bubbles of vapour form at discrete points, and critical heat flux boiling where the boiling surface is heated above a certain critical temperature and a film of vapor forms on the surface. Transition boiling is an intermediate, unstable form of boiling with elements of both types. The boiling point of water is 100 °C or 212 °F, but is lower with the decreased atmospheric pressure found at higher altitudes.
Boiling water is used as a method of making it potable by killing microbes that may be present. The sensitivity of different micro-organisms to heat varies, but if water is held at 70 °C (158 °F) for ten minutes, many organisms are killed, but some are more resistant to heat and require one minute at the boiling point of water. Clostridium spores can survive this treatment, but as the infection caused by this microbe is not water-borne, this is not a problem.
Boiling is also used in cooking. Foods suitable for boiling include vegetables, starchy foods such as rice, noodles and potatoes, eggs, meats, sauces, stocks and soups. As a cooking method it is simple and suitable for large scale cookery. Tough meats or poultry can be given a long, slow cooking and a nutritious stock is produced. Disadvantages include loss of water-soluble vitamins and minerals. Commercially prepared foodstuffs are sometimes packed in polythene sachets and sold as "boil-in-the-bag" products.
Two or more atoms<span> may </span>bond<span> with each other to form a molecule. When two hydrogens and an oxygen share electrons via covalent </span>bonds<span>, a water molecule is formed. Chemical reactions </span>occur<span> when two or more </span>atoms bond<span> together to form molecules or when bonded </span>atoms are broken<span> apart.</span>
<span>We are given the initial amount of 1 million carbon-14 atoms and the final amount which is 1/16 of the current atmospheric 14C levels. Also, the half life of carbon is </span>5,750 years. WE can use the decay formula
Aₓ = A₀e^-(ln2/t1/2)t
1,000,000(1/16) = (1,000,000)e^-(ln2/5750)t
t = 23,000 years
Answer:
True
Explanation:
lithium atoms lose one electron each while chlorine atoms gain one electron each
Answer:
10°C
Explanation:
Heat gain by water = Heat lost by the slice of pizza
Thus,
<u>For water: </u>
Volume = 50.0 L
Density of water= 1 kg/L
So, mass of the water:
Mass of water = 50 kg
Specific heat of water = 1 kcal/kg°C
ΔT = ?
For slice of pizza:
Q = 500 kcal
So,
ΔT = 10°C
Increase in temperature = 10°C
