All categories

2 years ago

What are the significance of metals in human life and civilization?

Chemistry

1 answer:

7nadin3 [17]2 years ago

5 0

Answer:

Metals have an important role in our daily life. The discovery of the metal is said to be the most important milestone in the history of human civilization. We cannot live without machines now. All machines are made up of metals. Machines reduce the work of man. Many modern facilities would not have been possible without metals. Most metals occur as their compounds in nature.

You might be interested in

A saline solution with a mass of 400 g has 30 g of NaCl dissolved in it. What is the mass/mass percent concentration of the solu

maria [59]

(g solute/g solution)*100 = % mass/mass

30 g / 400 * 100

0,075 * 100

= 7,5% w/w

hope this helps!

3 0

3 years ago

Which atomic models does Rutherford’s experimental evidence support? Explain why these models (Dalton, Bohr, Thomson models) are

ipn [44]

Answer:

Rutherford was the first scientist who proposed the nuclear model of the atom. According to his atomic model, most of the space of an atom is empty, while the nucleus containing protons and neutrons lie at the center of the atom while electrons revolve around nucleus in definite orbits.

If we talk about studies of some other scientists like Dalton, Neil Bohr and JJ Thomson, they all are compatible with Rutherford's results to a large extent.

For example: Dalton's atomic model assumed that atoms of any substance are similar in size and atoms react to form compounds. Rutherford's concept indicated that atoms contain electrons and they are in a specific number which can be shared to form compounds.

If we talk about Bohr's model, it states that electrons revolve around nucleus in specific shells, this again is compatible with Rutherford's results which gave the concept of shells.

If we talk about Thomson's Plum pudding model, that describe atom as negative particles floating within a soup of diffuse positive charge. This is also compatible with the results of Rutherford that state that negative electrons surround positive nucleus.

Rutherford's model was best atomic model but still it took help from many previous studies and therefore was compatible with the results of old models.

Hope it help!

5 0

3 years ago

Read 2 more answers

A sample of oxygen gas is compressed from 30.6 L to 1.8 L at constant temperature pressure of 1.8 atm. Calculate the amount of e

ad-work [718]

Answer:

the change in the internal energy of the system is 3,752.67 J

Explanation:

Given;

initial volume of the gas, V₁ = 30.6 L

final volume of the gas, V₂ = 1.8 L

constant pressure of the gas, P = 1.8 atm

Energy released by the system, Q = 1.5 kJ = 1,500 J

Apply pressure-volume work equation, to determine the work done on the gas;

w = -PΔV

w = -P(V₂ - V₁)

w = - 1.8 atm(1.8 L - 30.6 L)

w = 51.84 L.atm

w = 51.84 L.atm x 101.325 J/L.atm

w = 5,252.67 J

The change in the internal energy of the system is calculated as;

ΔU = Q + w

Since the heat is given out, Q = - 1,500 J

ΔU = -1,500 J + 5,252.67 J

ΔU = 3,752.67 J

Therefore, the change in the internal energy of the system is 3,752.67 J

3 0

2 years ago

An indicator helps us to see the _____ during a titration experiment by causing a color change

Liula [17]

Answer:

Point of neutralization.

Explanation:

Indicators are used in titration experiments to show when the solution's pH is changing. For instance, a common indicator, phenolphthalein, turns pink in basic solutions, while it remains colorless in acidic solutions. The solution would turn a very light shade of pink when the pH reached above 7.

5 0

2 years ago

What is the mass of silver (107.87 g/mol) produced by the reaction of 3.00 moles of copper with 3.00 moles of silver nitrate?Cu

vladimir2022 [97]

Answer: 323.61 g of $Ag$ will be produced