SSC (Marathi Semi-English) १० वीं कक्षा - Maharashtra State Board Important Questions for Science and Technology 1

Answer the following question.
a) What is meant by corrosion?
b) Write names of any two methods of prevention of corrosion.
c) In which method, metal like copper, aluminium are coated with a thin layer of their oxides by means of electrolysis.
d) Explain this method with diagram.

Find the odd man out:

Choose the correct alternative and rewrite the following:

Iron is _____________________.

Answer the following question:
What is corrosion? Do gold ornaments corrode? Justify.

Write a short note on Alloying.

Observe the following picture and answer the following questions:

1. What is rust?
2. Write the chemical formula of rust.
3. Write the reaction of oxidation of iron at the anode.
4. Write the reaction of oxidation of iron at the cathode.
5. What is corrosion?

Extraction of moderately reactive elements is done by _______ and _______ method.

Write scientific reason.

On exposure to air, silver articles turn blackish after some time.

Explain the characteristics of ionic compounds.

Complete flow chart given below.

Answer the questions on the following passage.

The minerals from which the metal can be separated economically are called ores. Ores contain many types of impurities such as soil, sand and rocky substances along with metal compounds. These impurities are called gangue.
Metals can be extracted from their ores by means of various methods of separation. The process of extraction of metal in a pure state from the ores is also a part of metallurgy.
Ores are taken out from the mines and the gangue is usually separated from the ore at the site itself by various methods. Then the ores are carried out to the place where metals are produced. Here metals are extracted in pure form. Then metals are further purified by different methods of purification. This entire process is called metallurgy. Most metals being reactive do not occur in nature in the free state but are found in combined state as their salts such as oxides, carbonates, sulphides, and nitrates. however, the most unreactive metals that are not affected by air, water and other natural factors like silver, gold, platinum, generally occur in a free state. The compounds of metals that occur in nature along with the impurities are called minerals.

1. What are ores?
2. Which processes are involved in the branch of metallurgy? What is metallurgy?
3. Which metals are found in a free state?
4. In what forms are metals found in combined state?
5. What is gangue?

Gold plated ornaments is the example of ______.

Find the odd one out:

Give scientific reasons.

Silver amalgam is used for filling dental cavities.

1. Name the anode and electrolyte used in this technique.
2. How can we make aluminium articles made resistant to corrosion?
3. Name the technique used to coat the aluminium articles.

Answer the questions based on the figure below:

1. Which reaction is shown in the figure?
2. Which gas is evolved in the reaction?
3. Give an example of reactants that rapidly show this reaction. Give equations.
4. Give an example of reactants that do not react rapidly.
5. In what condition will reactants of (c) part react? Give equation.

In ______ process a layer of molten tin is deposited on metals.

Corrosion can be prevented by using ……………. solution.

The chemical formula for rust is.............. .

What is meant by rust?