An atom is the basic unit of matter and the specific structure of an element. The term "atoms" comes from the Greek "indivisible" meaning "indivisible" because, at the time, the Greeks considered the atom as the smallest and most indivisible thing in the universe. But we now know that atoms are made up of three types of particles: protons, neutrons, and electrons, and we also know that they also consist of smaller particles (such as quarks). The atom formed after the big bang 13.7 billion years ago. As the warm, dense universe begins to expand, it cools, allowing conditions to form quarks and electrons. Quarks come together to form protons and neutrons that are incorporated into the nucleus. According to CERN, all this happened in the very first minutes of the universe.
It took 380,000 years for the universe to cool down enough to slow down the electrons so that the nucleus could absorb them to form the first atom. The original atoms were hydrogen and helium, which are still the most abundant elements in the universe. Gravity then begins to control the cloud of gas to form stars, which form heavier atoms (this process continues until today), and the death of stars is called (supernova), spreading its precious content In the universe. chemistry analysis
An atom is the smallest unit of matter that contains all the chemical elements of an element. An atom consists of a positively charged proton nucleus, a moderately charged neutron, and a negatively charged electron, all of which run around the nucleus. The typical atomic size of protons and neutrons (if they contain electrons) that compose them is about 0.1 nanometers, and most of them are empty spaces in which we can find electrons; generally, small atoms have a similar shape. What is the sphere? The atom consists of two regions.
Saturday, 2 November 2019
Friday, 1 November 2019
Alkali metals
Alkali metals are known as elements of the first group in the periodic table, except hydrogen, which includes lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs) and francium (Fr). The characteristics of alkali metals include:
Since these metals are alkali metals when they interact with water, the hydrogen atom separates into the water molecule to form hydrogen, while the other hydrogen atom bonds with oxygen to form hydroxide.
All the elements of the first group in the periodic table have a valence electron, and the electronic distribution has s1, which means that it participates in chemical reactions.
The alkali metals are bright, soft enough to cut the knife, and generally, have a white color, but cesium is a yellowish-white color, and when placed in the flame, most of them give distinctive colors, for example, lithium shines bright red, and sodium appears yellow. The heated potassium gives violet, dark red and light blue cesium rubidium, so it is possible to differentiate these metals according to the colors they produce when they are heated.
Sodium is the sixth most abundant element on Earth (2.6%), potassium is the seventh (2.4%), lithium and rubidium are considerably less abundant, and cesium is a very rare element. With very small amounts of uranium minerals. chemistry analysis
Alkali metals are highly reactive elements, so they are found in nature with other elements, and some simple minerals that contain them such as halite (sodium chloride), sulfite (potassium chloride) and carnalite (potassium chloride, chloride magnesium) dissolve in water. , making metals easy to extract and purify, but complex and water-insoluble minerals are more abundant in the earth's crust.
Alkali metals react easily with oxygen and water vapor in the atmosphere (lithium also reacts with atmospheric nitrogen), react strongly, often violently with water to produce hydrogen, form strong caustic solutions and react with non-material. most common metallic such as halogens and sulfur. Halogens and phosphorus also interact with many organic compounds, especially those that contain halogen, or a hydrogen atom that is easy to replace.
Alkali metals tend to form positively charged ions (cations) when they interact with nonmetals, resulting in the production of highly meltable compounds, which are solid crystals that are interconnected by ionic bonds that result from the forces of mutual attraction between charges. positive and negative electrical.
Since these metals are alkali metals when they interact with water, the hydrogen atom separates into the water molecule to form hydrogen, while the other hydrogen atom bonds with oxygen to form hydroxide.
All the elements of the first group in the periodic table have a valence electron, and the electronic distribution has s1, which means that it participates in chemical reactions.
The alkali metals are bright, soft enough to cut the knife, and generally, have a white color, but cesium is a yellowish-white color, and when placed in the flame, most of them give distinctive colors, for example, lithium shines bright red, and sodium appears yellow. The heated potassium gives violet, dark red and light blue cesium rubidium, so it is possible to differentiate these metals according to the colors they produce when they are heated.
Sodium is the sixth most abundant element on Earth (2.6%), potassium is the seventh (2.4%), lithium and rubidium are considerably less abundant, and cesium is a very rare element. With very small amounts of uranium minerals. chemistry analysis
Alkali metals are highly reactive elements, so they are found in nature with other elements, and some simple minerals that contain them such as halite (sodium chloride), sulfite (potassium chloride) and carnalite (potassium chloride, chloride magnesium) dissolve in water. , making metals easy to extract and purify, but complex and water-insoluble minerals are more abundant in the earth's crust.
Alkali metals react easily with oxygen and water vapor in the atmosphere (lithium also reacts with atmospheric nitrogen), react strongly, often violently with water to produce hydrogen, form strong caustic solutions and react with non-material. most common metallic such as halogens and sulfur. Halogens and phosphorus also interact with many organic compounds, especially those that contain halogen, or a hydrogen atom that is easy to replace.
Alkali metals tend to form positively charged ions (cations) when they interact with nonmetals, resulting in the production of highly meltable compounds, which are solid crystals that are interconnected by ionic bonds that result from the forces of mutual attraction between charges. positive and negative electrical.
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