Elements
Trending Questions
- By freezing it
- By cooling it
- By heating it
- By stirring it
Bromine is the only non-metal which is liquid at room temperature.
True
False
The number of elements present in a water molecule are ______.
three
two
four
one
When a white compound ‘X’ is placed under sunlight, it turns grey. Give the name of the reaction and write the balanced chemical equation.
Explain why, hydrogen and oxygen are considered elements whereas water is not considered an element.
Carbon dioxide is a mixture a compound and not a mixture explain
Glucose is a compound containing carbon, hydrogen, oxygen and nitrogen.
- True
- False
There are three substances X, Y and Z. The substance X does not have a fixed melting point or boiling point and it still shows the individual properties of its constituents. The substance Y is a pure substance which occurs in nature as such. The substance Y has a fixed melting point and boiling point but it cannot be broken down into simpler substances by any chemical means. The substance Z is also a pure substance whose properties are entirely different from those of its constituents. The substance Z can, however, be divided by electrolysis into two substances which belong to the same class of substances as Y.
(a) What type of substance could X be? Name one substance like X.
(b) What type of substance could Y be? Name one substance like Y.
(c) What type of substance could Z be? Name one substance like Z.
(d) Which process involves absorption or release of an appreciable amount of energy: formation of substances X or formation of substance Z?
(e) Name the three groups into which all the substances like Y are divided on the basis of their properties.
Which of the following statement is true for elements?
They are pure substances.
They cannot be broken down into simpler substances.
They are classified into metals, non metals and metalloids.
All of the above
Give the names of the elements present in the following compounds:
(d) Potassium sulphate
please explain .
- Mercury
- Calcium
- Gold
- Zinc
Why are cooking utensils and water boiler are made up of Copper and Aluminium metal?
An element is made up of only one kind of __________
The element which is not common between the compounds called baking soda and soda ash is
(a) sodium (b) hydrogen (c) oxygen (d) carbon
(a) What is meant by (i) elements (ii) compounds, and (iii) mixtures? Write down the names of two elements, two compounds and two mixtures.
(b) Classify the following into elements, compounds and mixtures :
Marble, Air, Gold, Brass, Sand, Diamond, Graphite, Petroleum, Common salt, Sea-water, Chalk
Why water is considered as compound and not an element
- non-metals
- metalloids
- alloys
- metals
Common salt sublimes on heating whereas ammonium chloride does not.
- True
- False
Classify the following into elements and compounds :
(i) H2O (ii) He (iii) Cl2 (iv) CO (v) Co
Mercury, gallium, cesium, bromine, lead, boron
The total number of element(s) which exist(s) in liquid state at room temperature is
- Three
- Four
- Two
- One
Classify the following as elements or compound :
Iron , Iron sulphide, Sulphur, Chalk, Washing soda, Sodium, Carbon, Urea
Which of the following substances are elements ?
Water, Salt, Mercury, Iron, Marble, Diamond, Wood, Nitrogen, Air, Graphite, Hydrogen, Oxygen, Sugar, Chlorine
Aluminium is a metal.
True
False
Who is the father of Physical Chemistry?
Which of the following substances are elements?
Air, water, hydrogen, ammonia, oxygen, marble, salt
