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3 years ago

Calculate the molecular weight of chalk.write any two advantages of mandeleev's periodic table?

1 answer:

5 0

Part (a):
Chalk has the chemical formula: CaCo₃
From the periodic table:
mass of Ca = 40 grams
mass of Co = 58.9 grams
Therefore:
molecular weight of chalk = 40 + 3(58.9) = 216.7 grams

Part (b):
Advantages of Mandeleev's periodic table:
1- Could predict the properties of elements easily based on its position in the periodic table
2- Elements were arranged systematically in order of increasing atomic mass which helped in the study and classification of elements
3- Even after the discovery of noble gases, no major changes needed to be done to the periodic table. Noble gases were inserted easily
4- He left room for other undiscovered elements based on his systematic approach in writing the table

Hope this helps :)

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Part 2 please and explain please

vekshin1

1) 7.15 * 10^6

since the exponent of the scientific notation is positive, move 6 places to the right.

so, 7.15 * 10^6 = 7150000

2) 3.03 * 10^-8

Since the exponent of the scientific notation is negative, move the decimal point 8 places to the left.

so, 3.03 * 10^-8 = 0.0000000303

3) 4.9 * 10^-1

since the exponent of the scientific notation is negative, move 1 decimal place to the left.

so, 4.9 * 10^-1 = 0.49

4) 2.886 * 10^5

since the exponent of the scientific notation is positive, move 5 decimal places to the right.

so, 2.886 * 10^5 = 288600

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2 years ago

A student was given four unknown solutions. Each solution was checked for. conductivity and tested with. phenolphthalein. The re

777dan777 [17]

Answer: (3) C

Explanation:

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2 years ago

¿Cuál es el número atómico del calcio? 4 Científico que propuso que los átomos eran esferas indivisibles e indestructibles. 6 Si

spayn [35]

Answer:

es una expresion de 52 necesito puntos para una pregunta sorry

Explanation:

12-12-12-14-1161-76-57-57-

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2 years ago

Does ice particles have high interparticle force of attraction? Justify your answer. please and

Schach [20]

Answer:

¿Las partículas de hielo tienen una alta fuerza de atracción entre partículas? Justifica tu respuesta

Explanation:

Dichos contenidos están presentes en los currículos de Física y Química de la educación básica, con independencia del marco legal, pues introducen al alumno en el conocimiento químico de la materia. Aunque la teoría cinética molecular obvia la composición atómica de las partículas, no deja de ser un contenido deseable para introducir a los alumnos en el mundo de la química pues permite diferenciar y establecer relaciones entre los niveles macro, micro y simbólico de la materia.

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2 years ago

Which of the following correctly represents the transmutation in which a curium-242 nucleus is bombarded with an alpha particle

Alekssandra [29.7K]

Answer: The chemical equation is written below.

Explanation:

Transmutation is defined as the process in which one chemical isotope gets converted to another chemical isotope. The number of protons or neutrons in the isotope gets changed.

The chemical equation for the reaction of curium-242 nucleus with alpha particle (helium nucleus) follows:

$_{96}^{242}\textrm{Cm}+_4^2\textrm{He}\rightarrow _{98}^{245}\textrm{Cf}+_0^1\textrm{n}$

The product formed in the nuclear reaction are californium-245 nucleus and a neutron particle.

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3 years ago