Metals do burn. In fact, most metals release a lot of heat when they burn and are hard to put out. For example, thermite is used to weld train rails together. The fuel in thermite is the metal aluminum. When thermite burns, the aluminum atoms bond with oxygen atoms to form aluminum oxide, releasing a lot of heat and light in the process. As another example, hand-held sparklers use aluminum, magnesium, or iron as the fuel. The flame of a sparkler looks different from the flame of a wood fire because metal tends to burn hotter, quicker, and more completely than wood. This is what gives a lit sparkler its distinctive sparkling flame. In fact, most fireworks contain metal fuels. As another example, old flash tubes used in photography were nothing more than burning bits of magnesium in a glass bulb. Also, the space shuttle's solid rocket boosters used aluminum as the fuel. Some metals, such as sodium, burn so well that we don't make everyday objects out of them. Any boy scout who has started a fire using steel wool can attest to the fact that metals burn.

Atoms do not always contain the same number of electrons and protons, although this state is common. When an atom has an equal number of electrons and protons, it has an equal number of negative electric charges (the electrons) and positive electric charges (the protons). The total electric charge of the atom is therefore zero and the atom is said to be neutral. In contrast, when an atom loses or gains an electron (or the rarer case of losing or gaining a proton, which requires a nuclear reaction), the total charges add up to something other than zero. The atom is then said to be electrically charged, or "ionized". There is a major difference between the neutral state and the ionized state. In the neutral state, an atom has little electromagnetic attraction to other atoms. Note that the electric field of a neutral atom is weak, but is not exactly zero because the atom is not a point particle. If another atom gets close enough to the atom, they may begin to share electrons. Chemically, we say that the atoms have formed bonds.

There is only one significant force at work in chemical reactions: the electromagnetic force. There are four fundamental forces in the universe: gravity, the electromagnetic force, the weak nuclear force and the strong nuclear force. Gravity is too weak to affect chemical reactions much, seeing as chemical reactions involve the rearranging of tiny atoms. Also, the nuclear forces don't play a role in chemical reactions. If a nuclear force becomes involved, then you are dealing with a nuclear reaction and not a chemical reaction. Every facet of chemistry is the result of one force: the electromagnetic force. However, because of the quantum wave nature of particles, this force can take on many forms. In a strict sense, every manifestation of the electromagnetic force is unique, as it depends crucially on the arrangement of atoms, the state of their electrons, their temperature, etc. To foster better understanding, however, chemists place the different forms of the electromagnetic force into broad classes:

Crystals are in fact very common. Take a look around you when you sit down to dinner. Your metal knife is a crystal, as are your spoons, forks, and metal serving bowls. The ice in your cup is a crystal, as is the salt in your shaker. Your ceramic plates and bowls are also crystals. Interestingly, your "crystal" wine cups are actually one of the few items in your house that are not crystal. Looking into the kitchen, you see your metal fridge, your metal sink, your granite counter tops, your tiled floor, your plaster walls, and your electronic gadgets – all crystal. In fact, aside from glass and organic material such as wood, cotton, or bamboo, almost all solids are crystal. There are even some liquids that are crystal, such as in your iPod screen. In science, the word "crystal" describes a material that has an ordered spatial arrangement of its molecules. For instance, salt molecules line up in straight columns and rows when forming a salt crystal. Almost all metals, ceramics, salts, rocks, and semiconductors form crystals when in the solid state. Glass, on the other hand, has its molecules randomly distributed. Organic materials such as wood and cotton have highly complex biological structures on the molecular level and therefore do not have the simple repeating patterns characteristic of crystals. But simple organic molecules, such as sugar, do form crystals if they are concentrated and solidified.

Hi,

There are many sunscreens available in the market which make very tough to choose the best among them. But on the basis of chemical free, we can filter easily and choose the best one.

Most of the sunscreens has silicones and parabens. If you want to chemical free sunscreen, then go for which ever is free from parabens and silicons.

Sunscreens available in India which are chemical free are listed below.

The Organic Pharmacy Cellular Protection Suncream SPF - 30

UnSun Mineral Tinted Face Sun Screen SPF - 30

Beauty Counter Dew-Skin Moisturizing Coverage.

Mama Earth Sunscreen

Saie Sunvisor

The Organic Pharmacy Cellular Protection Suncream SPF - 50.

Beauty Counter Counter-sun Mineral Sun Screen Lotion, SPF - 30.

May this information was useful to you.

Good Luck!!

The answer to this question really depends on your situation. Let us state the question more concretely: we have a clean, wet load of laundry that just got washed. We want to dry the clothes as quickly as possible but only have the option of hanging up the clothes to dry. Would it be quicker to dry the clothes by hanging them indoors or outdoors? Before we can make sense of the answer to this question, we need to review the basics.

The breaking of chemical bonds never releases energy to the external environment. Energy is only released when chemical bonds are formed. In general, a chemical reaction involves two steps: 1) the original chemical bonds between the atoms are broken, and 2) new bonds are formed. These two steps are sometimes lumped into one event for simplicity, but they are really two separate events. For instance, when you burn methane (natural gas) in your stove, the methane is reacting with oxygen to form carbon dioxide and water

The hole in the ozone over Antarctica still exists, but it is no longer the threat it once was according to an October 2012 NASA press release. According to NASA, the hole appears and disappears every year due to a complex interplay of seasonal weather patterns. Ozone blocks most of the harmful ultraviolet rays from the sun, which would otherwise reach earth's surface and cause more skin cancer. The hole in the ozone, which in reality is more like a region of partial depletion than a complete hole, was dangerously increasing in size in the 1980's and 1990's. Research indicated that use of man-made CFC chemicals such as found in aerosol cans contributed to depleting the ozone. As a result the U.S. banned the use of CFC's in aerosol cans in 1978. Other countries have imposed similar CFC bans and efforts to enact additional bans are under way. As a consequence of these legal measures, the hole in the ozone stopped expanding from year to year and is slowly shrinking back to its 1980's state.

Hello,

Hope you are doing well.

Difference between Chemical and Physical process is as such:

• In Physical Processes, composition remains same whereas in Chemical Processes composition changes.
• Physical processes are reversible and temporary while Chemical processes are irreversible and permanent.
• In physical processes no new substance is formed, whereas in Chemical process new substances may be formed.
• A physical processes involves very little to no absorption of energy whereas during a chemical reaction, absorption and evolution of energy take place.
• Physical processes do not involve the production of energy while during Chemical process production of energy in the form of light, heat or sound is formed.

Example of Physical process- freezing of water, melting of wax, boiling of water, etc.

Example of Chemical process- digestion of food, burning of coal, rusting, etc.

Hope this helps you. All the best!

Tomato juice does not make skunk odor go away. More specifically, tomato juice does not react chemically with the skunk odor to destroy it. Instead, it simply has a strong enough smell on its own to partially mask the skunk smell. But in this respect, it is no different from any other strong odor. Perfume or scented candles will do just as well as tomato juice to mask the skunk smell. As soon as the tomato juice scent wears away, the skunk odor becomes noticeable again. A better approach is to deactivate the skunk spray through chemical reactions. Your allies in this effort are bleach, hydrogen peroxide, and backing soda. Wash clothes and fabrics that have the skunk smell in bleach. To clean hard surfaces that have the skunk odor, spray on a cleaning solution that contains bleach, let it sit, and then wipe off. To clean items that can not withstand bleach, such as pet fur or colored clothes, instead use a hydrogen peroxide/baking soda solution. Combine one quart of 3% hydrogen peroxide, 1/4 cup baking soda and 2 tbsp. liquid dish detergent for an excellent skunk odor killer that is safe enough to bath pets in. For best results, this solution should be scrubbed into the fur or fabric while still foaming. Note that this mixture is potentially explosive if left to sit too long in a sealed container. Discard the unused portion instead of storing it.