In which of the following is the symbol for the ion and the number of electrons it contains given correctly?

Air pressure is lowest in the lungs during whi h of the following points during inspiration or expiration

AlladinOne [14]

Answer:

Inspiration

Explanation:

This question is on application of Boyle's law; <u>pressure is inversely proportional to volume</u>.when we inhale air, the diaphragm and the muscles in the ribs contract thus increasing the volume in the lungs.Increased volume of the lungs cause the pressure to decrease.During exhaling, the diaphragm and muscles in the ribs relax, making the lungs to recoil and reduce in volume to force air out.Pressure in the lungs is increased than that in the environment making air to move out.

4 0

2 years ago

At constant pressure, which of these systems do work on the surroundings? A ( s ) + B ( s ) ⟶ C ( g ) A(s)+B(s)⟶C(g) 2 A ( g ) +

Tju [1.3M]

Correct question:

At constant pressure, which of these systems do work on the surroundings?

(a) A ( s ) + B ( s ) ⟶ C ( g )

(b) 2 A ( g ) + 2 B ( g ) ⟶ 5 C ( g )

(c) A ( g ) + B ( g ) ⟶ C ( g )

(d) 2 A ( g ) + 2 B ( g ) ⟶ 3 C ( g )

Answer:

(a) A ( s ) + B ( s ) ⟶ C ( g )

(b) 2 A ( g ) + 2 B ( g ) ⟶ 5 C ( g )

Explanation:

Work done by a system on the surroundings at a constant pressure is given as;

W = -PΔV

Where;

ΔV is gas expansion, that is final volume of the gas minus initial volume of the gas must be greater than zero.

Part (a)

A ( s ) + B ( s ) ⟶ C ( g )

ΔV = 1 - (0) = 1 (expansion)

Part (b)

2 A ( g ) + 2 B ( g ) ⟶ 5 C ( g )

ΔV = 5 - ( 2+ 2) = 1 (expansion)

Part (c)

A ( g ) + B ( g ) ⟶ C ( g )

ΔV = 1 - ( 1 + 1) = -1 (compression)

Part (d)

2 A ( g ) + 2 B ( g ) ⟶ 3 C ( g )

ΔV = 3 - ( 4) = -1 (compression)

Thus, systems where there is gas expansion are in part (a) and part (b). The correct answers are:

(a) A ( s ) + B ( s ) ⟶ C ( g )

(b) 2 A ( g ) + 2 B ( g ) ⟶ 5 C ( g )

4 0

2 years ago

What are the effects on the bodies of water? use terms algal bloom, dead zone and hypotoxic

Anna35 [415]

Water pollution is defined as the mixing of water with unwanted substances and that makes water unsafe.

Water pollution includes runoff of excess fertilizers,

herbicides, and insecticides from agricultural lands

and residential areas; oil, grease, and toxic chemicals

from urban runoff and energy production; and

sediment from improperly managed construction sites,

crop and forest lands, and eroding stream banks.

Polluted waters have high BOD which affects aquatic biodiversity.

Hpotoxic substances such as lead, arsenic, and fluoride cause many problems to aquatic animals and humans. Water contaminated with Arsenic results in diseases such as arsenicosis. Fluoride had been reported to cause depression in DNA and RNA synthesis in cultured cells, significant reductions in DNA and RNA levels, and conditions including aging, cancer, and arteriosclerosis are associated with DNA damage and its disrepair. Lead causes problems related to the central nervous system. Children and pregnant women are most at risk. Routine applications of fertilizers and pesticides for agriculture and uncontrolled runoff in water bodies. Adds nitrogen and phosphorus to water. It adds nitrogen and phosphorus to water causing eutrophication and algal blooms.