Question

help to solve this worksheet​

Answer 1

Answer:

a.)40.043%,12%,47.957%

b.)elements symbols = K,Ba,Al,Ca,C,F,L,Zn,I,S2

valency in serial = 1,2,3,2,3,1,2,1,2

c.) the smallest unit in which a substance can be divided without changing its chemical forms is called molecule

Answer 2

Answer:

Explanation:

Q2.Potasium

Symbol=K

Valency=1

Barium

Symbol=Ba

Valency=2

Aluminium

Symbol=Al

Valency=3

Calcium

Symbol=Ca

Valency=2

Cobalt

Symbol=Co

Valency=1

Flourine

Symbol=F

Valency=1

Lead

Symbol=Pb

Valency=2

Zinc

Symbol=Zn

Valency=2

Iodine

Symbol=I

Valency=1

Sulphide

Symbol=S2-

Valency=2

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Q3. Molecules:

A molecule is an electrically neutral group of two or more atoms held together by chemical bonds. Molecules are distinguished from ions by their lack of electrical charge.

Arrangement of constituent atoms in the molecules:

The atoms in a molecules are chemically bonded in a definite pattern. This arrangement of atoms is given by the structural formula of the compound. For example, structural formula for water is H-O-H . This is the simple illustration for the structure of water. In fact water water and all other molecules exhibit definite spatial arrangements depending on the nature of chemical bonding between atoms.

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Q4.a)Atom:

Neutrally charged

Ion:

Positively or negatively charged

b)Example for cation:

• Sodium (Na+)

Example for anion:

• Bromide (Br-)

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Q5. Law of multiple proportions:

Law of multiple proportions, statement that when two elements combine with each other to form more than one compound, the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers. For example, there are five distinct oxides of nitrogen, and the weights of oxygen in combination with 14 grams of nitrogen are, in increasing order, 8, 16, 24, 32, and 40 grams, or in a ratio of 1, 2, 3, 4, 5. The law was announced (1803) by the English chemist John Dalton, and its confirmation for a wide range of compounds served as the most powerful argument in support of Dalton’s theory that matter consists of indivisible atoms.

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Q6. i)Example for monovalent cation:

• Na+

ii)Example for Bivalent cation:

• Mg2+

iii)Example for monovalent anion:

• Br-

iv)Example for bivalent anion:

• Mg2-

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Q7.  Ionic compounds:

An ionic compound is a chemical compound composed of ions held together by electrostatic forces termed ionic bonding. The compound is neutral overall, but consists of positively charged ions called cations and negatively charged ions called anions.

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