Chemistry
Physics
Biology
Earth Science
100
When 2 molecules of hydrogen react completely with 1 molecule of oxygen, water is formed.
After the reaction, which statement about the number of atoms is correct?
A. The number of oxygen atoms decreases.
B. The total number of hydrogen atoms increases.
C. The total number of atoms remains the same.
D. The total number of atoms decreases by half.
C. The total number of atoms remains the same.
100
What does the symbol below represent in a circuit diagram?
Single cell
or
Cell
100
Which scientist proposed the theory of natural selection?
Charles Darwin
100
What is the protective layer in the stratosphere that absorbs harmful UV rays?
Ozone
200
Why does sugar dissolve faster in hot water than in cold water?
Higher temperatures increase the kinetic energy of water molecules, helping them break down the sugar molecules faster.
In hot water the molecules move faster
200
What is the difference between one point of compression and corresponding on the next compression in a sound wave called?
Wavelength
200
Which organelle is called the “powerhouse of the cell”?
Mitochondria
200
What is the study of how living things interact with each other and their environment?
Ecology
300
Which statement correctly explains why elements in the same group of the periodic table have similar chemical properties?
A. They have the same number of neutrons.
B. They have the same number of electrons in their outermost shell.
C. They have the same atomic number.
D. They have the same number of electron shells.
B. They have the same number of electrons in their outermost shell.
300
The tendency of an object to resist a change in motion is called.
Inertia
300
Which blood vessel carries oxygenated blood from the lungs to the heart?
Pulmonary vein
300
Which greenhouse gas traps significantly more heat per molecule than CO2?
Methane
400
What is the common name and formula of the gas that turns limewater milky?
Carbon dioxide (CO2)
400
The bending of waves as they pass through different materials is called.
Refraction
400
What is the nitrogen- fixing bacteria in root nodules of legumes called?
Rhizobium
400
What is the term for the site where waste is buried under the ground in a controlled way to isolate it from the environment, reduce pollution, and manage disposal of solid waste?
Landfill/ sanitary landfill
500
Why do noble gases not form ions under normal conditions?
As they have a complete valence shell which make them chemically inert.
Octect
500
A skydiver reaches a constant speed when gravity balances air resistance. What is this called?
Terminal velocity
500
In which part of the respiratory system, gaseous exchange takes place?
Alveoli/ Air sacs in the lungs
500
What is the gradual increase in the concentration of phosphorus, nitrogen, and other plant nutrients in an aging aquatic ecosystem such as a lake?
Eutrophication