1
A substance that is soft at room temperature?
Rubber
An alloy used in making cooking pots
stainless steel alloy
An inactive metal
The mass of unit volume of a substance
Density
The temperature at which the matter begins to change from liquid state to gaseous state
Boiling point
G.R.F: When you open a perfume bottle, you smell it all over the room?
Because the molecules of perfume are in a continuous motion and keeps the properties of matter
A solution that is a good conductor of electricity
Acidic solution
Alkaline solution
salt solution
The simplest pure form of matter that can't be decomposed into simpler form
Element
The monoatomic liquid
Mercury
what's meant by the melting point of ice equals 00C
This means that the ice begins to change from solid state to liquid state at 00C
What happens when?
The number of protons change
The atomic number and mass number change and the atom changes
The forces that binds the molecules of a matter
Intermolecular forces
G.R.F. The nucleus is positively charged?
Because it contains positive protons and neutral neutrons
The diatomic liquid
Bromine
Two inactive (inert) gases
Helium
Neon
Argon
Xenon
A piece of iron of mass 78 grams was immersed in a cylinder containing 140 cm3 of water, so the water rises to 150 cm3.
V= V2-V1=150 - 140 = 10 cm3
D=M/V =78/10 = 7.8 gm/cm3
G.R.F.: Melting of solid on heating
because solid particles gain heat energy, so the motion of molecules speed up, the intermolecular forces weakens and the intermolecular spaces increase, so it changes into liquid.
The disappearance of salt molecules when left in water for a period of time
due to the spreading of salt molecules among the intermolecular spaces between water molecules
Calculate the mass of a piece of copper if the density of this piece is 2.5 gm/cm3 and its volume is 4 cm3
Mass= D x V = 2.5 x 4 = 10 grams
G.R.F. Cooking pots are made of aluminum?
Because it is a good conductor so it allows heat to flow through it
G.R.F. The symbol of potassium is K not Po
Because it is named according to its latin name
G.R.F: The K level is filled with electrons before L level?
Because K has less energy than L
The less active metals
iron - aluminum - copper
G.R.F: Sodium and potassium are kept under kerosene?
To prevent their reaction with moist air
G.R.F. The atom is electrically neutral
Because the number of positive protons inside the nucleus equal the number of negative electrons around the nucleus