General Science GK Questions with Answers – Page 31

Each product has been linked to the chemical paired with it. Lead has been found as a trace contaminant in many lipsticks, coming from colour pigments; since lipstick is swallowed in small amounts, regular use raises concern because lead is a toxic heavy metal that harms the nervous system.

In anodizing the clean aluminium article is indeed the anode, but oxygen is released at the anode, not at the cathode; hydrogen is released at the cathode.

The statement that the sensitivity of the human ear does not vary with frequency is false, because the ear is far more sensitive to some frequencies than to others.

Kwashiorkor is a disease of protein deficiency in a child who still gets enough calories. It usually appears when a child is weaned from breast milk onto a starchy diet with little protein.

Arranged from most acidic to most basic, the four substances fall in exactly this order. Lemon juice, rich in citric acid, has a pH of about 2 to 2.5.

Scurvy is caused by a lack of vitamin C, or ascorbic acid, which the body needs to make collagen, the protein that holds skin, gums and blood vessels together.

Chloropropane has two carbon–carbon bonds, seven carbon–hydrogen bonds and one carbon–chlorine bond, all single covalent bonds, making 10 in total.

Beats are heard when two sound waves of slightly different frequencies overlap, so their combined loudness rises and falls regularly.

Fleming's right-hand rule is used for electromagnetic induction, as in a generator, and its middle finger gives the direction of the current induced in the conductor.

NCERT's Class 10 chemistry chapter on acids, bases and salts states that our body works within the narrow pH range of 7.0 to 7.8, which is slightly basic.

The bronchi only carry air between the windpipe and the lungs; their walls are too thick for oxygen and carbon dioxide to pass into the blood, so no gas exchange happens there.

All four are parts of the two complex permanent tissues of plants: tracheids and vessels belong to xylem, while sieve tubes and companion cells belong to phloem.

Sunlight takes about 8 minutes and 20 seconds, roughly 500 seconds, to travel from the Sun to the Earth. The average distance between the Sun and the Earth is about 150 million kilometres, a distance called one astronomical unit.

In 1665 Hooke looked at a thin slice of cork under his self-made microscope, saw tiny box-like compartments and named them cells, from the Latin word cella, meaning a small room.

This is false because viruses have no chlorophyll, no cell organelles and no metabolism of their own, so they cannot make food in any way.

This statement is false, because diamond is an electrical insulator: all four valence electrons of each carbon atom are locked in covalent bonds, leaving no free electrons to carry current.

Starlight bends as it passes through layers of air of changing temperature and density, and because these layers keep moving, the star's apparent position and brightness flicker.

Buoyancy, also called upthrust, is the upward force that a liquid or gas exerts on any object placed in it.

After fertilisation each structure of the flower turns into the next stage in exactly this way. When a male gamete from the pollen tube fuses with the egg cell inside the ovule, the fertilised egg becomes the zygote.

Water gas is made by passing steam over red-hot coke, and the reaction C + H₂O → CO + H₂ gives carbon monoxide and hydrogen in roughly equal volumes.