Table of Contents
- 1 What happens to the molecules of a compound when it changes?
- 2 Does the number of molecules change?
- 3 What happened to the molecules as you switch between solid liquid and gas?
- 4 Which of following would cause the molecules in matter to change?
- 5 How do the molecules of a compound differ from the molecules of an element?
- 6 What is the difference between the molecules of an element and the molecules of a compound Give one example of each?
- 7 What is the difference between molecular formula and empirical formula?
- 8 How do you count the number of atoms in a formula?
What happens to the molecules of a compound when it changes?
What happens to the molecules of a compound when it changes state from liquid to solid? The molecules lose energy and as a result, slow down and become closer together.
Does the number of molecules change?
Explanation: The Law of Conservation of Mass and Energy (“matter can neither be created nor destroyed”) clearly states that a chemical change cannot alter the number of atoms in a given reaction. The atoms can only rearrange so that it can yield a new molecule/compound but the number of atoms should stay the same.
What is the relationship between a molecule and compound?
A molecule is a group of two or more atoms held together by chemical bonds. A compound is a substance which is formed by two or more different types of elements which are united chemically in a fixed proportion. All molecules are not compounds.
Do compounds have the same formula?
Compounds that have the same molecular formula but different chemical structures are called isomers. Depending on what types of differences there are between the structures, it is possible to classify isomers into various sub-types.
What happened to the molecules as you switch between solid liquid and gas?
The molecules take extra energy, called the heat of fusion, to liquefy. All the energy at this point goes into making the substance a liquid. They require energy, called the heat of vaporization, to make the transition to gas. Once all of the substance makes the transition, more energy raises the temperature again.
Which of following would cause the molecules in matter to change?
When energy is added (e.g. heat energy, that will then be transformed into kinetic energy), the molecules start moving and vibrating more causing the strength of the bonds to decrease.
Can a chemical formula be changed?
No—you cannot change the formulas of individual substances, because the chemical formula for a given substance is characteristic of that substance. What you can do, however, is to change the number of molecules that react or are produced.
Does the number of atoms change after a chemical reaction?
The number and type of atoms are the same before and after a chemical reaction. The number and type of atoms are different before and after a chemical reaction. The type of atoms is the same before and after a chemical reaction, but the number of atoms can change.
How do the molecules of a compound differ from the molecules of an element?
The only difference between a molecule of a compound and a molecule of an element is that in a molecule of an element, all the atoms are the same. For example, in a molecule of water (a compound), there is one oxygen atom and two hydrogen atoms. But in a molecule of oxygen (an element), both of the atoms are oxygen.
What is the difference between the molecules of an element and the molecules of a compound Give one example of each?
Molecules of an element contains the same kind of atoms,e.g. P4 is a molecules of element which contains all four atoms of phosphorus. Molecules of a compound contains two or more kinds of atoms, e.g. H2O is molecules of compound which contains 2 atoms of hydrogen and 1 atom of oxygen.
Can two compounds have the same chemical formula but be different substances Why or why not?
It is important to be aware that it may be possible for the same atoms to be arranged in different ways: Compounds with the same molecular formula may have different atom-to-atom bonding and therefore different structures. For example, could there be another compound with the same formula as acetic acid, C2H4O2?
Can molecules have the same formula but have different molecular structures?
1. Isomers. Isomers are compounds with identical chemical formulae, but different structures. They are very important in air pollution chemistry, because even slightly different structures can evoke dramatic differences in chemical and physical properties.
What is the difference between molecular formula and empirical formula?
If the molecular formula cannot be simplified into a smaller whole-number ratio, as in the case of H 2 O or P 2 O 5, then the empirical formula is also the molecular formula. A chemical formula is an expression that shows the elements in a compound and the relative proportions of those elements.
How do you count the number of atoms in a formula?
To count the total number of atoms for formulas with polyatomic ions enclosed in parenthesis, use the subscript as a multiplier for each atom or number of atoms. A molecular formula is a chemical formula of a molecular compound that shows the kinds and numbers of atoms present in a molecule of the compound.
What is a subscript in a chemical formula?
A chemical formula is an expression that shows the elements in a compound and the relative proportions of those elements. If only one atom of a specific type is present, no subscript is used. For atoms that have two or more of a specific type of atom present, a subscript is written after the symbol for that atom.
What is a chemical formula for water?
A chemical formula is an expression that shows the elements in a compound and the relative proportions of those elements. Water is composed of hydrogen and oxygen in a 2:1 ratio.