Simple and compound substances
Simple substances are made up of just one chemical element; when you have two or more elements in the composition, the substances are composed. The study of chemical reactions from...
The periodic properties of chemical elements are the characteristics they have. Note that the chemical elements of the periodic table have a specific location that varies with the...
Test your knowledge of the types of mixes with the 10 questions below. Also check the comments after the feedback to answer your questions about the topic. Question 1 Consider the...
Centrifugation is a method of separating heterogeneous mixtures of solids from liquids or from liquids only. One of the most important factors in centrifugation is density. That...
The electron distribution or electron configuration the way chemical elements are ordered considering the number of electrons they have and their proximity to the nucleus...
The mass number, indicated by the capital letter A, corresponds to the sum of the protons (Z) and the neutrons of a given chemical element in the periodic table. Since electrons,...
Levitation, sieving and ventilation are methods of separating heterogeneous mixtures. Through levigating and ventilation it is possible to separate the denser substance from the less dense...
Electronegativity is a periodic property that indicates the atom's tendency to attract electrons. It happens when the atom is in a covalent chemical bond, that is, in the...
A pure substance is formed by a single type of chemical species, that is, its composition and properties are fixed. A mixture contains more than one type of component and therefore its...
The density of water is 1 g/cm3 (it reads: one gram per cubic centimeter). This value corresponds to water at 25 ºC, since at lower temperatures the water density decreases. Other factors...
Chromatography is a process of separating and identifying components of a mixture. This technique is based on the migration of compounds from the mixture, which have different...
Molecule is a set of atoms, the same or different, joined by covalent bonds. These chemical species are electrically neutral and represent the forming unit of a...
Density is the concentration of matter in a given volume. Mathematically, this quantity is expressed by: It is a specific property that considers the ratio between the mass (m) and...
Ionization energy is a periodic property that indicates how much energy is needed to transfer an electron from an atom to a ground state. An atom is in its state...
In Chemistry, the Weight Laws include the “Proust's Law” and the “Lavoisier's Law”. Both contributed to the advancement of Chemistry as a science so that they introduced the method...
Stoichiometry is responsible for the quantitative analysis of the composition of substances consumed and formed in a chemical reaction. The stoichiometric calculation establishes a relationship between...
Decantation is a method of separating heterogeneous mixtures between solid-liquid and liquid-liquid. Decanting process The decanting process is based on leaving the mixture in...
Chemistry laboratories have different equipment, glassware, devices and devices that allow the performance of numerous activities with greater precision and safety. Know the names...
Scavenging is a method of separating solid heterogeneous mixtures. This process, which separates solid substances from other solid substances (solid + solid), is made of...
Alkali metals are chemical elements present in the first group of the periodic table, called the 1A family. They get this name because they easily react with water, forming substances...
Sublimation is the change from the solid state to the gaseous state and vice versa, without going through the liquid state. For a substance to undergo the sublimation process it must be...
Flotation is a method of separating solid and liquid heterogeneous mixtures. For this purpose, air bubbles are inserted into the liquid, in which one of the elements adheres and ends up separating...
Fusion is the change from the solid state to the liquid state. It occurs when a body, subjected to a given pressure, receives heat and its temperature reaches a certain value. The amount of...
Electron (e- or β−) is a particle that constitutes the atom, that is, it is a subatomic particle. It has a negative charge and is located in the electrosphere, around the atomic nucleus, which...
Hydrogen is located in the first house of the periodic table and is represented by the letter H, which is its symbol. Despite its importance, it is the simplest element, formed only...
Matter is everything that has mass and occupies a place in space, that is, matter has volume and mass. Examples of matter are: trees, stars, air, a chair, a bicycle,...
Atomic mass is the standard way to measure the mass of atoms, expressed in atomic mass units (u). Chemists decided to take carbon as their base, which is why it is said that atomic mass...
Noble gases, also called "rare gases", make up the elements of group 18 (family 8A) of the periodic table. The main characteristic of noble gases is the difficulty that they...
Chemical bonds are classified as polar or non-polar. While every ionic bond is polar, the polarity of the covalent bond depends on the atoms present in the molecule. One...
Filtration is a method of separating heterogeneous solid-liquid and gas-solid mixtures. It is the most common method of separating an insoluble solid from a liquid. At the...
The atomic radius of elements is a periodic property that determines the radius of an atom which varies depending on the element's position in the Periodic Table. So they can increase and...
Glassware is one of the most used materials in the Chemistry laboratory to carry out mixtures, reactions and tests. They have different formats, capacities and functions, being used in...
Solidification is the change from the liquid state to the solid state. For solidification to occur, it is necessary that, being subjected to a given pressure, the body loses heat until it reaches...
Alchemy is a practice of a mystical character that flourished during the Middle Ages, bringing together science, art and magic. One of his main goals was to obtain the elixir of life in order to guarantee...
Proton (p+) is one of the small particles that make up the atom, which is the smallest particle of a chemical element. The proton, or proton (according to European Portuguese), is formed by three...
Density is a physical property of materials that relates mass to occupied volume, mathematically expressed by:. Take advantage of this list of 12 questions for you to test your...
Allotropy is the chemical property that allows the formation of one or more different simple substances from the same chemical element. Examples of allotropy are: carbon, from...
Distillation is one of the processes of separation of homogeneous mixtures that takes place through boiling, where the liquid is vaporized and then condensed. Thus, the mixtures that will be separated...
Molecular mass (MM) corresponds to the mass of a molecule (consisting of atoms) relative to the atomic mass unit (u), that is, equal to 1/12 of the mass of an atom of carbon-12 isotope...
Electronic Affinity or Electroaffinity is a periodic property that indicates the amount of energy released when an electron is received by an atom. This atom meets...
Neutron (n) is a small particle that makes up the nucleus of the atom. It has no charge and is made up of even smaller particles, which are called quarks. The neutron, or neutron (in...
Copper is a chemical element with the symbol Cu, atomic number 29, atomic mass 63.55 and belonging to group 11 of the periodic table. Copper can undergo different types of chemical reactions and...
Combustion is an exothermic chemical reaction between two regents, fuel and oxidizer, in which energy is released in the form of heat. Fuel: It is the oxidizable substance,...
Atomic models emerged from the need to explain the structure of atoms. When new evidence on the constitution of atoms was presented, a new atomic model tried...
Halogens, on the periodic table, correspond to the elements of group 17 or Family VII A. What are Halogens? Halogens are formed by 6...
Nitrogen (nitrogen, from the Greek "a", without and "zoe", life), which means "salt-former" or "that which forms nitrates". It is one of the most abundant elements in the Universe. On Earth it is at its greatest...
Rutherford (1871-1937) was a New Zealand physicist. In 1899, researching uranium he discovered alpha radiation and beta radiation. It laid the foundations for the theory of radioactivity. Revolutionized the...
Evaporation is the transition from a liquid to a gaseous state. It occurs on the free surface of liquids, slowly and gradually, at any temperature. A substance when it's in...
Chemistry is the science that studies matter, its structure, formation and the transformations it undergoes, taking into account the energy involved in the entire process. Chemistry is part of...
In a physical phenomenon, the substance maintains its identity, as the change only occurs in its shape. The chemical phenomenon is characterized by the formation of a new substance, that is, the...
