IGCSE Chemistry: Specimen Questions with Answers 22 - 24 of 240

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Question 22

Question

MCQ▾

Which element is a metal?

Choices

Choice (4)

a.

Image for Element of Metal: Choice A

b.

Image for Element of Metal: Choice B

c.

Image for Element of Metal: Choice C

d.

Image for Element of Metal: Choice D

Answer

b.

Explanation

Correct option is B i.e.. charge on element ion is + ve and electrical conductivity is high because metal always donate the electron so charge comes on that and it has free electrons so it is also a good conductor of heat and electricity.

Question 23

Write in Short

Short Answer▾

Substances can be classified as:

Elements can be divided into:

Define each of the following terms:

Element (2 marks)

Explanation

Each of more than one hundred substances that cannot be chemically interconverted or broken down into simpler substances and are primary constituents of matter. Each element is distinguished by its atomic number, i.e.. the number of protons in the nuclei of its atoms.

Question 24

Question

MCQ▾

Two indicators, bromophenol blue and Congo red, show the following colors in acidic solutions and in alkaline solutions.

Table of Two Indicators

A few drops of each indicator are added to separate samples of a solution of pH-2. What are the colors of the indicators in this solution?

Choices

Choice (4)

a.

Image Showing Solution of pH-2: Choice A

b.

Image Showing Solution of pH-2: Choice B

c.

Image Showing Solution of pH-2: Choice C

d.

Image Showing Solution of pH-2: Choice D

Answer

d.

Explanation

Correct option is D Ph2 means acidic substance so bromophenol blue turns to yellow as above data. And congo red to violet.

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