1. Atoms
The atom is a basic unit of matter, made up of nuclei and negatively charged electron cloud surrounding it. Atomic nucleus consists of positively charged protons and electrically neutral neutrons (except in the atomic nuclei of hydrogen-1, which has no neutrons). Atoms are the number of protons and electrons at neutral, while the number of protons and electrons of different positive or negative and is referred to as an ion. Atoms are grouped by the number of protons and neutrons contained in the nucleus. The number of protons in an atom determines the element kimiaatom, and the number of neutrons determines the isotope of the element.
2. Elements
The element is a single chemical substance can not be decomposed into other substances. Some examples are the elements oxygen, nitrogen, hydrogen, iron, aluminum, gold, silver, mercury and platinum. The natural elements are generally present in the form of compounds, such as hydrogen, for example contained in the water and carbohydrates. Some elements such as oxygen, nitrogen, sulfur, gold, and platinum in addition to compounds also exist in the free state. As we know, oxygen and nitrogen contained in the air.
The element itself is divided over the metals and non-metals, some examples of the metal element is aluminum, iron (ferum), gold (aurum), silver (arguntum), and mercury (hidrargirum).
Metallic element has properties such as:
Except mercury, everything is a solid at room temperature (25 degrees Celsius)
A good conductor of electricity and heat
Shiny if rubbed
Some examples of non-metallic element is nitrogen, Oxygen, Carbon, Sulfur (sulfur) and chlorine. The non-metallic element has properties such as:
• Which is a solid generally brittle, such as charcoal (carbon)
• Nothing is a solid, liquid, or gaseous substance at room temperature (25 degrees Celsius)
• Not shiny when rubbed, except diamonds (another form of carbon)
3. Molecule
Molecule a combination of two or more atoms (same or different) that are covalently bonded. A molecule the smallest independent component neutral material. Monatomic molecule comprising one atom example, Ne, Mg,K. More polyatomic molecules consist of atoms example, CO2. The simplest molecule is part of a compound which still has the properties of compound formation.
4. Compound
A compound is a substance composed of two or more elements that combine chemically with certain mass ratio. Some examples of compound are air, table sugar, table salt.
5. Mixtures
Mixtures are two or more substance that are not chemically combined. The mixture is a combination that occurred on some substance with a comparison that is not fixed and without chemical reaction. The mixture is divided into two types, namely a mixture of homogeneous and heterogeneous mixtures.
• Homogenous mixture is a mixture consisting of two or more substances that when constituent particles that can not be distinguished. This homogeneous mixture is often also referred to as a solution. For example: vinegar, sugar water, brine and others.
• Heterogeneous mixture is a mixture of two or more kinds of substances constituent particles are still distinguishable from one another. , For example: land, water and oil, water with sand.
Hi Iggi
BalasHapuswhether always atom consists of protons, neutrons, and electrons? please mention any explanation and example?
Thank you
Yes, always atomic nucleus consists of positively charged protons, electrons and neutrons are electrically neutral (except the atomic nucleus of hydrogen-1, which has no neutrons)
HapusFor example: Li, Na, K, Rb, and others (except the atomic nucleus of hydrogen-1, which has no neutrons)
Assalamualaikum .. hi inggi .. how are you ?
BalasHapusplease ... explain . what are characteristic of kovalen bond , and give the example ?? ..
Thanks ..
Waalaikumsalam jelpa, I'm fine. Okay I will answer the question.
HapusCharacteristics of covalent compounds, namely:
1. covalent compounds having a boiling point and low freezing point
2. Solubility in water
3. It does not conduct electricity
4. Can forming polymer or macromolecule
Examples of covalent compounds = H2O, NH3, Alcohol, HCl, HF, HBr, Sucrose, SO2, Methanol, Acetone, Acid Format, Acetic Acid, N2O5, Cl2O5 etc.
Hi nggi
BalasHapusHow to distinguish molecules are polar and nonpolar Which?
Differences Between Polar and Non-polar
Hapus1. Substance polar electrical charge which is quite positive and negative atoms, while the non-polar substances have no electrical charge that much.
2. The polar substance will be mixed with polar substances but polar substances will not mix with non-polar substances.
3. Examples of polar substances are water and alcohol. An example of a non-polar substance is oil.
hi inggi, I want to ask, why aluminum metals include reactive metals corrosion resistant air?
BalasHapusBecause aluminum metal surface has a thin oxide layer is strong, this is the thin layer that protects the aluminum metal to air, in the sense of thin oxide layer is strong enough to withstand oxygen so as not to form further oxidation (corrosion events). Besides not being able to react with air, aluminum metal also does not react with water because of the thin layer of oxide.
HapusThis oxide layer formation by means of electrolytically superimposed on aluminum process occurs naturally, the process is called "anodizing process". To thicken the oxide layer can be performed by anodizing process, in which the Al metal anodizing process is used as the anode in the electrolysis using H2SO4 solution. O2 gas that is formed will react with the anode to produce Al2O3 layer
Aluminum is a metal that easily reacts with air and water. It can be seen from the nature of the aluminum reductant is quite good, and the price of its reduction potential (E ° = -1.66 volt) negative enough to readily react with water and oxygen
2Al(s) + 3H2O Al2O3(s) + 3H2(g)
4Al(s) + 3O2(g) 2Al2O3(s)
but due to the thin oxide layer, then aluminum can not react with air and water.
A thin layer of aluminum oxide on the surface, a thin layer of Al2O3 has a 10-8 meters thick that is impermeable to water, thus protecting the metal surface from further reaction. (This is in contrast with Fe2O3 iron rust porous and permeable, which causes rust metal parts below are not protected against oxygen and water vapor). As a result, the aluminum metal is quite stable and durable for use in a wide range of equipment
As we know that there are compounds called covalent and ionic compounds. Can you give some difference and give examples
BalasHapusIonic Compounds:
Hapus- bonding between the metal and non-metal
- boiling point and high melting point
- it is a solid at room temperature
- in a pure state is conductor
- soluble in water
For example: salt (NaCl), NaBr, KBr, KI and others
Compounds COVALENT:
- the bond between the non-metallic and non-metallic
- boiling point and low melting point
- having 3 form that is solid, liquid, and gas
For example: H2O, NH3, Alcohol, HCl, HF, HBr, Sucrose, SO2, Methanol, Acetone, Acid Format, Acetic Acid, N2O5, Cl2O5 etc.
Why covalent coordination prevalent in transition element ion compound?
BalasHapusOne of the properties of the transition element is that it has a tendency to form complex ions or complex compounds. The ions of transition metal elements have empty orbitals that can accept electron pairs on bonding with certain molecules or anions to form complex ions
HapusHi Inggi, please explain to me about spessifically difference from metals, non-metals and metallic element ? thanks.
BalasHapus1. Metallic elements
HapusCharacter :
- good electrical conductors
- Shiny
- Can be forged and stretched
- At room temperature, solids except mercury
- It has a melting point and a high boiling point
2. The non-metal elements
Character :
- Electrical insulators
- Not shiny
- Usually break if forged and can not be stretched
- At room temperature are liquid and gas, but there is solid
- It has a boiling point and a low melting point