Advertisements
Advertisements
Question
A change in the physical state can be brought about
Options
only when energy is given to the system
only when energy is taken out from the system
when energy is either given to or taken out from the system
without any energy change
Advertisements
Solution
when energy is either given to or taken out from the system
When energy is given to the system the solid state changes to liquid. When energy is taken out from a liquid it changes to solid e.g., ice changes to water and water to water vapours when heat energy is given. Water vapours or steam condense to water and water freezes to ice when energy is decreased.
APPEARS IN
RELATED QUESTIONS
Write the names of `("NH"_4)_2"SO"_4` compounds:
Fill in the blank:
Atoms are _____
Name the particles which revolve around the nucleus.
Name three non-metals/radicals which have valency -1, -2, and -3.
Fill in the blank
If an atom loses an electron, it acquires ______ a charge.
Fill in the blank
An _______ is electrically neutral.
State two observations which show that atom is not indivisible.
The electronic configuration of an element Z is 2, 8, 8.
(a) What is the atomic number of the element?
(b) State whether element Z is a metal or a non-metal.
(c) What type of ion (if any) will be formed by an atom of element Z? Why?
(d) What is special about the outermost electron shell of the atom of this element?
(e) Give the name and symbol of element Z.
(f) Name the group of elements to which Z belongs.
Select the correct answer to the statement given below:
The smallest particle of a substance – capable of independent existence and which retains the characteristics of the substance.
The electronic structure [configuration] of fluorine can be written as 2, 7. In a similar way give the electronic configuration of aluminium
The electronic structure [configuration] of fluorine can be written as 2, 7. In a similar way give the electronic configuration of phosphorus
A compound containing one atom of carbon and two atoms of oxygen is ______.
The basic unit of matter is ______.
State true or false. If false, correct the statement.
The basic unit of an element is molecule.
Define the term ions or radicals.
A sample of vitamic C is known to contain 2.58 ×1024 oxygen atoms. How many moles of oxygen atoms are present in the sample?
An atom of Oxygen (O) and two atoms of hydrogen (H.) combine to form a molecule of ______.
Lead is also known as plumbum.
The ______ are combination of atoms of various elements or the same element.
