Write the symbols of : Lead, Gold, Helium
Pb, Au, He
Write the electronic configuration , its chemical activity.
2,8 ,8,1 / Active
GR: Energy level "L" is filled with electron before energy level "M".
because "L" has less energy than "M"
Complete:When a piece of wood is put into a fire and starts to burn, ......................energy starts to decrease.
chemical energy.
Which change in state is shown in the diagram?
Melting
Which form of energy does a substance usually gain or lose to undergo a change of state?
Thermal energy
Complete according to the figure: During the process of condensation, the change happens from ...........to...............
c / b
An atom of phosphorus has the chemical symbol 3 1 1 5 P .What is the atomic number,mass number, no.of electron, no of neutron.
15, 31, 15, 16
An atom contains 10 electrons. How many of these electrons occupy the "M" energy level?
zero
How does the solar energy reaches from The Sun to Mars planet?
Radiation
What is this element? is it monoatomic or diatomic?
Argon, Monoatomic
What happens to the K.E when doubling the speed of an object and decrease of the speed to the half
K.E increases to the double.
Complete: At the maximum height of the object, the ....................vanished.
K.E
GR: Sodium must be kept under kerosene surface?
to prevent their reaction with atmospheric oxygen
