Correct answer: Loss of electrons. Oxidation is loss of electrons (OIL RIG: Oxidation Is Loss).
Correct answer: Excretion. Excretion removes wastes like urea and carbon dioxide from the body.
Correct answer: Fixed joint. The cranial bones are united by immovable fixed joints called sutures.
Correct answer: 70-300 km. Shallow quakes are below 70 km, intermediate 70-300 km, deep 300-700 km.
Correct answer: Stratosphere. The ozone layer in the stratosphere absorbs most UV radiation.
Correct answer: Light travels much faster than sound. Light moves at about 3×10^8 m/s, while sound moves at about 340 m/s in air.
Correct answer: Newton. Isaac Newton formulated the three laws of motion in the Principia (1687).
Correct answer: Stratosphere. The ozone layer lies in the stratosphere and absorbs harmful ultraviolet radiation.
Correct answer: Water. Cholera spreads through water or food contaminated with Vibrio cholerae bacteria.
Correct answer: Vaccination. Vaccination prevents these infectious diseases (for example, through the DPT and MMR vaccines).
Correct answer: High pitch. Pitch depends on frequency: the higher the frequency, the higher the pitch.
Correct answer: Mixture. Chromatography separates the components of a mixture.
Correct answer: Guglielmo Marconi. Guglielmo Marconi is credited with developing the first practical radio (wireless telegraphy) in the 1890s.
MAVEN is a NASA mission studying the Martian atmosphere.
TB is primarily a lung (pulmonary) infectious disease.
The tongue is often cited as the body's most flexible/agile muscle.
Keratin is the structural protein forming nails, hair, and skin's outer layer.
Glucose is the primary sugar circulating in blood for energy.
Proteins form the structural building blocks of muscles and organs.
The U.S. Space Force maintains 31 operational GPS satellites, above the 24-satellite baseline requirement.
The decibel is the standard logarithmic unit for sound intensity.
Humans have seven cervical vertebrae.
Microgravity lets spinal cartilage discs expand, temporarily increasing height.
The correct answer is Coordinate. In the compound Al₂Cl₆, the bond between the two AlCl₃ molecules is a coordinate covalent bond (also called a dative bond). This occurs when one AlCl₃ molecule shares a pair of electrons from a chlorine atom with the electron‑deficient aluminum atom of the other AlCl₃ molecule. Each aluminum atom is bonded to four chlorine atoms through coordinate bonds, resulting in a bridged structure. Ionic and covalent bonds exist within the AlCl₃ units, but the bond between the molecules is coordinate. Therefore, the correct type of bond is coordinate.
Explanation: The correct answer is 4.
The four commonly recognized primary states of matter are:
Why the other options are incorrect:
Therefore, 4 (solid, liquid, gas, plasma) is the correct answer for commonly recognized primary states of matter.