File Name: list of chemical compounds and their formulas .zip
The Play dough recipe provided in Gr. This first section is a revision of what learners should have covered in previous grades. It spans several pages, but it is mostly revision and has been included as a reference for learners.
You will need to decide, based on your class, about how much time you need to dedicate revising these topics, or whether you get your learners to read over the content and complete the activity at the end. Can you remember learning about compounds in Gr. We will start this chapter by summarising and revising some of the main ideas about elements and compounds from Gr.
This should help us to link the new ideas in this chapter to what we already know. Learners need to be made aware that compounds may occur as two types of structures, namely molecules and lattices:. In this section we have included a brief mention of crystal lattices to avoid the misconception later that NaCl and other ionic compounds consist of molecules.
Learners should know that NaCl, for instance, consists of a regular arrangement of sodium and chloride atoms combined in a ratio, packed to form a crystal structure. The particles of a compound always consist of two or more atoms. In Physical Sciences Gr. In some cases they can form molecules. You may remember that 'molecule'is the word scientists use for a cluster of atoms that stick together in a specific way.
Other compounds consist of atoms which are arranged in a regular pattern called a crystal lattice. The molecules of a compound always consist of two or more different kindsof atoms, like the molecules of water in the following diagram. Compounds that form crystal lattices consist of many atoms, but they always combine in a fixed ratio. For example, in sodium chloride table salt , there is one chlorine atom for every sodium atom in the crystal. The smallest 'unit' that is repeated in the crystal consists of one Na and one Cl.
The formula NaCl represents one 'formula unit' of NaCl. From the diagram of the water molecules and the sodium chloride lattice above, we can see that a compound is not simply a mixture of elements. A mixture of the elements hydrogen and oxygen would look like this:. Why are the hydrogen and oxygen atoms paired in the diagram above? Before we answer that question, here is an important reminder: Elements are made up of just one kind of atom. Some elements exist as diatomic molecules, like the ones in the diagram on the right below and the hydrogen and oxygen molecules in the 'mixture' diagram above.
Diatomic means 'consisting of two atoms '. Can you see that the water molecules in the diagram above are all identical? That brings us to the next point about compounds. In water, for example, one oxygen atom O has combined with two hydrogen atoms H. All water molecules are exactly the same in this respect. Any other combination of hydrogen and oxygen atoms would NOT be water. For example, hydrogen peroxide consists of the same elements as water hydrogen and oxygen but the ratio is different: two oxygen atoms have combined with two hydrogen atoms.
Water can be represented by the formula H 2 O. The formula tells us that two hydrogen atoms H are combined with one oxygen atom O in a molecule of water. What is the formula of hydrogen peroxide? Can you remember the name of the compound with the formula CO 2? Remember to take notes as you discuss things in class! The formula of hydrogen peroxide is H 2 O 2. The formula CO 2 is carbon dioxide. What holds the clusters of atoms that we call molecules together?
When atoms combine to form molecules, they do so because they experience an attractive force between them. The forces that hold atoms together are called chemical bonds.
In all chemical reactions, the atoms in molecules rearrange themselves to form new molecules. This is how compounds form: the atoms in one set of compounds separate as bonds break between them, and they get rearranged into new groups as new bonds form. When this happens, we say a chemical reaction has occurred. Look at the following illustration. In the example above, the elements to the left of the arrow are called the reactants.
They have rearranged to form a new compound. This is called the product and it is shown to the right of the arrow. Can you describe what happened to the atoms and the bonds in this reaction? Discuss which bond broke, which ones formed, and how the atoms were rearranged during the reaction. The final aspect of compounds that we learnt in Gr. Compare the formula for water with the diagram of the water molecule you saw earlier. Can you make the connection? The chemical formula of a compound is the same for all the molecules of that compound.
When we read the formula, the subscripts tell us how many atoms of a particular element is in one molecule of that compound:. When we write H 2 O, we actually mean H 2 O 1. According to convention, we do not use 1 as subscript in formulae and so the first formula is the correct one. What it means is that there are 2 hydrogens to every 1 oxygen. This is also a ratio and can be written as We will practise writing formulae in the next activity. What are the reactants and what is the product in this reaction?
Write these names onto the diagram. The two circles each represent an oxygen atom as oxygen is a diatomic molecule meaning it exists as two oxygen atoms bonded together in diatomic molecules. Magnesium oxide has the formula MgO.
It means that for every 1 magnesium atom, there is 1 oxygen atom joined to it in a chemical bond. Now that we have refreshed our memories, we are going to return to the table that scientists use to organise their knowledge about the elements. Can you remember what it is called? The first part of this section is a revision of what learners should have covered in previous grades.
We learnt about the origins of the Periodic Table in Gr. Let's also revise what we learnt then, so that we have a firm foundation for our new learning. The Periodic Table is basically a chart that scientists use to list the known elements.
The table consists of individual tiles for each of the elements. What information can we find on the Periodic Table? That is what the next section is all about. The diagram below shows an example of one of the tiles on the Periodic Table. Can you identify the element it represents?
How many protons does it have in its atoms? The atomic number Z is usually written at the top of each tile for an element in the Periodic Table, and the larger atomic mass number A is written at the bottom of each tile.
There is a large version of the Periodic Table printed on the inside cover of your workbooks for you to easily refer to. There are different versions of the Periodic Table, which can each contain different information about the elements.
Can you identify what information is provided about the elements in the following table? An interactive site on the Periodic Table. The elements are arranged in order of increasing atomic number. The elements with the largest atomic number are found at the bottom of the table.
The elements are also arranged in regions and these regions are often presented in different colours. The following Periodic Table shows us where the metals, non-metals and semi-metals can be found. Now that we have revised what we already learnt in previous grades, let's learn some new characteristics of the Periodic Table. All tables have rows and columns. Can you remember the difference between vertical and horizontal?
Draw short lines to show the difference between 'vertical' and 'horizontal' in the following table. Vertical runs 'up and down', and horizontal runs 'from side to side'. In a conventional table the columns run vertically, and the rows run horizontally. There are special words to describe the columns and rows of the Periodic Table. The following diagram shows what the column and rows are called. Groups: The vertical columns of the Periodic Table are called groups. The groups on the Periodic Table are numbered in such a way that Group 1 is on the left.
How many groups are there? The groups are numbered from 1 to
The Play dough recipe provided in Gr. This first section is a revision of what learners should have covered in previous grades. It spans several pages, but it is mostly revision and has been included as a reference for learners. You will need to decide, based on your class, about how much time you need to dedicate revising these topics, or whether you get your learners to read over the content and complete the activity at the end. Can you remember learning about compounds in Gr. We will start this chapter by summarising and revising some of the main ideas about elements and compounds from Gr.
The common names and formulas of chemical compounds is a very relevant area of study for every competitive exam including SSC and it is important for the aspirants to develop a fair idea on this subject. In this article, we are discussing the following topics. A chemical compound is a chemical substance composed of many identical molecules composed of atoms from more than one element held together by chemical bonds. There will be a fixed ratio for a chemical compound determining the composition of it. For example, water H2O is a compound consisting of two hydrogen atoms bonded to an oxygen atom.
Common Chemical Compounds – Names and Formulas. Free GK E-book. Current Affairs and General Awareness section is one of the most important and high.
In a pure chemical. ChemCatalyst The cards show a sodium ion and three polyatomic ions. This section includes elements from all parts of the periodic table.
In this lesson we will learn how to write and interpret chemical formulas for elements and compounds. Lowercase or capital letter? It makes a big difference in chemistry! Sometimes the same type of atom can appear in more than one place in a molecular formula.
If you keep an eye on the latest trend followed by SSC for General Awareness questions , you would notice that Science facts are covering major portions of it. To help you quickly take a look at List of Chemical Formulas and their Common Names , we are providing you in this article. To help you attempt the chemistry questions without any glitches, we are sharing with you a detailed list of Chemical Formulas and their Common Names. Chemical formulas are expressions which state the number and types of atoms present in a molecule of a substance. Before moving ahead have a look at the Chemical compounds.
Think about what you call your friends. Some of your friends might have full names long names and a nickname short name. These are the words we use to tell others who or what we are referring to. Their full name is like the substances name and their nickname is like the substances formulae. Without these names your friends would have no idea which of them you are referring to. Chemical substances have names, just like people have names. This helps scientists to communicate efficiently.
- Беккеру нравилось это немецкое слово, означающее убийство. От него так и веяло холодом. - Ermordung. Он… он был?. - Да, убит. - Но… но это невозможно! - У немца перехватило дыхание. - Я там .
Звонок был сделан из страны с кодом один - из Соединенных Штатов. Нуматака удовлетворенно мотнул головой.