Скачать или смотреть 14. Elements, Components and Mixtures Part 2 Exercise 5 and 6 7th General Science easy Answer state

14. Elements, Components and Mixtures Part 2 Exercise 5 and 6 7th General Science easy Answer state

1. Who are my companions?
Group ‘A’ Group ‘B’
1. Stainless steel (a) Non-metal
2. Silver (b) Compound
3. Bhajani mixture (c) Mixture
for milling
4. Salt (d) Element
5. Coal (e) Alloy
6. Hydrogen (f) Metal
2. Write the names of elements from the
following symbols : Zn, Cd, Xe, Br, Ti,
Cu, Fe, Si, Ir, Pt.
3. What are the molecular formulae of the
following compounds ?
Hydrochloric acid, sulphuric acid, sodium
chloride, glucose, methane.
4. Give scientific reasons.
(a) Buttermilk is churned to get butter.
(b) In chromatography, the ingredients of
a mixture rise up to a limited height
when water rises up to the upper end
of the paper.
(c) A wet cloth is wrapped around a water
storage container in summer.
5. Explain the difference.
(a) Metals and non-metals
(b) Mixtures and compounds
(c) Atoms and molecules
(d) Separation by distillation and by
separating funnel
6. Write answers to the following questions
in your own words.
(a) How are the components of mixtures
separated by simple methods ?
(b) Which elements (metals and non-
metals), compounds and mixtures do
we use in our day-to-day life ?
(c) In everyday life, where and for what
purpose do we use centrifugation?
(d) Where are the methods of separation
by distillation and by separating
funnel used? Why ?
(e) Which precaution will you take while
using the methods of distillation and
separation by separating funnel ?