General Science Mixed Quiz: Set 37

A quantity that has both magnitude and direction is a vector, and momentum, which is the product of mass and velocity, is a vector because velocity has a direction.

The middle ear holds three tiny bones, the smallest in the human body, called the malleus, the incus and the stapes, which in everyday English are the hammer, the anvil and the stirrup.

A reading of 113 on the Fahrenheit scale works out to 45 degrees Celsius, and adding 273 to that gives about 318 K. Fahrenheit is turned into Celsius with the relation C = (F - 32) x 5/9, so (113 - 32) x 5/9 = 81 x 5/9 = 45…

A unisexual flower carries only one kind of reproductive organ, either stamens or a pistil, while a bisexual flower carries both.

Distilled water has had its dissolved salts removed, so it holds almost no free ions to carry charge and does not conduct electricity.

The grooves cut into a sole grip the ground, so the foot does not slip while walking or running. Friction is the force that acts between two surfaces in contact and opposes motion between them.

The halogens are placed in Group 17 of the modern periodic table. This family has five members - fluorine, chlorine, bromine, iodine and astatine.

The domestic goat is treated as a subspecies of the wild goat, so its name carries three parts — the genus Capra, the species aegagrus and the subspecies hircus.

The balanced equation is 2FeSO4 → Fe2O3 + SO2 + SO3, so p = 2, q = 1, r = 1 and s = 1.

Crown gall is caused by the bacterium Agrobacterium tumefaciens, which enters through a wound near the base, or crown, of the stem and makes the plant grow rough tumour-like swellings there.

Ammonium chloride is the salt of a strong acid, hydrochloric acid, and a weak base, ammonium hydroxide, so its aqueous solution is acidic and its pH is less than 7.

A nuclear reactor splits heavy atoms; it burns no fuel, so it releases no carbon dioxide and needs no equipment to cut such emissions.

Iodine is the non-metal in the antiseptic painted on cuts and wounds, sold as tincture of iodine, which is a solution of iodine in alcohol.

In the colour code used for fire extinguishers, a black band or label marks a carbon dioxide extinguisher. The body of the cylinder is signal red and a coloured patch near the label tells you the filling at a glance, so the right cylinder can be picked in a hurry.

Vegetable oils contain unsaturated chains with carbon to carbon double bonds; hydrogen adds across those double bonds in the presence of nickel or palladium, turning them into single bonds, so the oil becomes saturated and sets into a solid fat.

At sunset the Sun is close to the horizon, so its light travels through a much thicker layer of atmosphere before it reaches the eye.

In graphite each carbon atom is joined to only three other carbon atoms in flat hexagonal layers, so the fourth valence electron of every atom is not used in bonding and can move freely along the layer.

In 1665 he cut a thin slice of cork, examined it under a microscope of his own making and saw rows of empty boxes, which he named cells after the small rooms of a monastery; the drawing and description appeared in his book Micrographia.

In the equation given, glucose reacts with oxygen to release carbon dioxide, water and energy, and the breakdown of food inside the cell to release energy is called respiration.

A shortage of iodine makes the thyroid gland in the neck swell, a condition called goitre. The thyroid needs iodine to make the hormone thyroxine, and when iodine is short the gland grows larger to trap whatever little is available, so the neck looks visibly swollen.