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4. molecules are neutral.
5. a term that means "without water" is anhydrous.
6. when an atom gains or loses electrons, the charged particle that results is called a molecule.
7. the formula so42- stands for ammonium.
. an atom is chemically unstable when its outer energy level contains all the electrons it can hold.
the chlorine atoms in hydrogen chloride have a stronger attraction for the electrons than the hydrogen atoms
do. the hydrogen chloride molecule is therefore a nonpolar covalent molecule.
an element's oxidation number indicates how many electrons the element must gain, lose, or share to become
etter of the choice that best completes the statement or answers the question.
a chemical formula, the number of each type of atom in the compound is shown by numbers called
c. oxidation numbers
4. Molecules are neutral. True
Molecules are neutral compounds that forms through the combination of two or more atoms. Molecules can be:
Monoatomic which is made of only one kind of atom e.g O₂
Diatomic which is made up of two kinds of atom
Polyatomic molecules are made up of more two atoms.
Molecules are electrically neutral and are formed as a result of covalent bonds.
5. A term that means "without water" is anhydrous. True
The term anhydrous refers to a compound without water. It usually used for crystalline compounds without water of crystallization. These water can influence chemical reactions to a large extent.
Hydrous is the opposite term and it refers to a compound that has water.
6. When an atom gains or loses electrons, the charged particle that results is called a molecule. False
When an atom gains or loses electrons the charged particles that results is called an ion.
An atom is made of protons, neutrons and electrons. The protons are the positively charged particles in an atom. Electrons are negatively charged and neutrons carry not charge.
When atoms gain electrons they become negatively charged because the number of electrons is now greater than that of protons. Negatively charged particles are called anions.
Positively charged particles are called cations.
7. The formula SO₄²⁻ stands for ammonium. False
The formula is not the formula for ammonium. This is tetraoxosulphate(VI) ion which is called a radical.
Ammonium ion is given as NH₄⁺
8. An atom is chemically unstable when its outer energy level contains all the electrons it can hold. False
An atom is chemically stable when its outer energy level contain all the electrons it can hold.
The noble gases have chemically stable atoms because their outer energy level contains all the electron they can hold. They follow the octet rule and achieve an inert status by filling their outermost shell.
Unstable atoms belongs to other groups on the periodic table because they require some number of electrons to fill them up and make them complete.
9. The chlorine atoms in hydrogen chloride have a stronger attraction for the electrons than the hydrogen atoms. True
Hydrogen and Chlorine forms hydrogen chloride by covalent bonds between their respective atoms.
Covalent bond forms by the sharing of electron by the two atoms.
In the bond between Chlorine and Hydrogen, the chlorine pulls the shared electrons more closer to itself. This is because chlorine has a higher electronegativity compared to hydrogen.
Elecronegativity is the readiness of an atom to attract electrons in a covalent bond more to itself.
This leaves a permanent positive charge on hydrogen and a negative charge on the chlorine.
10. An element's oxidation number indicates how many electrons the element must gain, lose, or share to become stable.
The oxidation number of an atom shows how many electron it will gain, loose or share to become a stable atom.
Oxidation number is very important when chemical bonds are forming. They are usually estimated based on the number of valence electrons in an atom.
When an atom gain, share or lose a certain number of electron, it will become stable. This number is depicted by the oxidation number.
Assigning oxidation number
In a chemical formula, the number of each type of atom in the compound is usually shown by the subscripts. The subscripts expresses the number of combining atoms that are involved in the formation of a compound.
The subscripts are derived from the combining powers of the atoms when the bonds are forming e.g
2 atoms of H and 1 atom of O
Option (C) is the correct answer.
A compound is a substance that contains atoms of two or more different elements which are chemically combined together in a fixed ratio by mass.
For example, NaCl, , etc are all compounds.
Atoms of a compound can be separated by chemical means.
Hence, we an conclude that the atoms can only combine in fixed ratios, and they can only be separated by a chemical change, correctly describes a compound.
1) centrifuge is used to separate mixtures which are heterogeneous in nature.
So here in the given examples
A) Cream and milk, because of their difference in density
2) sterling silver is a homogenous mixture alloy.
So answer is A homogeneous mixture, because the different components are mixed and evenly within the substance
3) Compound is when atoms combine by chemical reaction and they lose their identity
2 atoms from the same are formed
2 new atoms different from the original atom are being formed.
3) a) The atoms are bonded together, and the compound has different physical and chemical properties than the individual elements.
A compound is when multiply elements bond together to create something new, that new substance has a new set of chemical properties and physical properties.
4. molecules are neutral.
5. a term that means "without water" is anhyd...