Which of the following is the number of protons in a lithium atom?

Diffusion down a concentration gradient causes most of the carbon dioxide from the blood to move into the alveoli.

The alveoli are tiny air sacs in the lungs where gas exchange occurs.

Carbon dioxide is a waste product of cellular respiration and is carried by the blood to the lungs to be exhaled.

In the lungs, carbon dioxide diffuses from the blood (where its concentration is high) into the alveoli (where its concentration is lower) down its concentration gradient.

Choice A is incorrect because carbon dioxide is not converted to carbon monoxide in the body.

Choice C is incorrect because passive transport using carrier proteins is not the primary mechanism by which carbon dioxide moves from the blood into the alveoli.

Choice D is incorrect because active transport using energy is not involved in the movement of carbon dioxide from the blood into the alveoli.

Osmosis is the movement of water molecules across a selectively permeable membrane from an area of higher water concentration to an area of lower water concentration.

In a hypertonic solution, the concentration of solutes outside the cell is higher than inside the cell, so water flows out of the cell through aquaporins embedded in the plasma membrane to balance the concentration gradient.

Choice A.

Facilitated diffusion is not correct because it is a type of passive transport that involves the movement of molecules across a membrane through specific transport proteins, but it does not specifically refer to the movement of water molecules.

Choice B.

Active transport is not correct because it is a type of transport that involves the movement of molecules against their concentration gradient and requires energy in the form of ATP, but osmosis is a passive process that does not require energy.

Choice D.

Diffusion is not correct because it refers to the movement of molecules from an area of higher concentration to an area of lower concentration, but it does not specifically refer to the movement of water molecules.

A myocardial infarction affects the coronary blood vessels of the heart.

A myocardial infarction, commonly known as a heart attack, occurs when blood flow decreases or stops in the coronary artery of the heart, causing damage to the heart muscle 1.

Choice B is incorrect because the aorta is not a blood vessel of the heart.

The aorta is the main artery that carries oxygenated blood from the heart to the rest of the body.

Choice C is incorrect because the pulmonary blood vessels are not affected by a myocardial infarction.

The pulmonary blood vessels carry deoxygenated blood from the heart to the lungs.

Choice D is incorrect because the vena cava is not a blood vessel of the heart.

The vena cava is a large vein that carries deoxygenated blood from the body to the heart.

The hypothalamus is a region of the brain that synthesizes antidiuretic hormone (ADH), also known as vasopressin.

ADH is then transported to the posterior pituitary gland via neurohypophysial capillaries, where it is stored until it is ready to be secreted into the circulation.

Choice A.

Pineal gland is not correct because it is a small endocrine gland located in the brain that secretes the hormone melatonin, which regulates sleep-wake cycles, but it does not synthesize ADH.

Choice B.

Thymus is not correct because it is a gland located in the chest that produces hormones involved in immune system development, but it does not synthesize ADH.

Choice D.

Pancreas is not correct because it is a gland located behind the stomach that secretes hormones such as insulin and glucagon, which regulate blood sugar levels, but it does not synthesize ADH.

Triple point.

In a phase diagram, the term used for a substance held at a temperature and pressure where the solid, liquid, and gaseous states of a substance exist simultaneously is the triple point.

The triple point is a unique point on a phase diagram where the three states of matter (solid, liquid, and gas) can coexist in equilibrium.

At the triple point, the temperature and pressure of the substance are fixed.

Option B, critical temperature, is the temperature at which a gas cannot be liquefied, regardless of the pressure applied.

It is a characteristic property of a substance and is typically higher than the boiling point of the liquid at standard pressure.

Option C, critical point, is the point on a phase diagram where the liquid and gas phases of a substance become indistinguishable.

At the critical point, the distinction between the liquid and gas phases disappears, and the substance becomes a supercritical fluid.

Option D, absolute zero, is the theoretical temperature at which all matter has zero thermal energy.

At absolute zero, all substances are in their solid state, but it is not relevant to a phase diagram, as it is a temperature where no transitions between states occur.

In summary, the term used for a substance held at a temperature and pressure where the solid, liquid, and gaseous states of a substance exist simultaneously in a phase diagram is the triple point, whereas the other options provided are not relevant or are characteristic properties of substances in different contexts.

As a solid turns to a liquid, the particles become less ordered and more free to move around.

Choice B is not correct because particles have an increase in mobility as a solid turns to a liquid.

Choice C is not correct because particles move further apart as a solid turns to a liquid.

Choice D is not correct because intermolecular forces between particles become weaker as a solid turns to a liquid.

The two major parts of the nervous system are the Central Nervous System (CNS) and the Peripheral Nervous System (PNS).

The CNS is made up of the brain and spinal cord and acts as the integration and command center of the body.

The PNS represents the conduit between the CNS and the body and is further subdivided into the somatic nervous system (SNS) and the autonomic nervous system (ANS).

Choice A is incorrect because it only mentions two subdivisions of the PNS, which are the autonomic nervous system (ANS) and somatic nervous system (SNS).

Choice B is incorrect because it only mentions one major part of the nervous system, which is the PNS, and one subdivision of it, which is the SNS.

Choice D is incorrect because it only mentions one major part of the nervous system, which is the CNS, and one subdivision of the PNS, which is the ANS.

Carbonic acid.

In the human body, maintaining the pH of the blood within a narrow range is critical for proper physiological functioning.

One of the buffering systems that helps to regulate blood pH involves the conversion of carbon dioxide (CO2) and water (H2O) into carbonic acid (H2CO3), which then dissociates into hydrogen ions (H+) and bicarbonate ions (HCO3-).

Carbonic acid (H2CO3) is responsible for donating H+ ions to act as a buffer when blood pH rises.

When blood pH rises (becomes more alkaline), carbonic acid dissociates, and the H+ ions combine with bicarbonate ions to form more carbonic acid.

This helps to remove excess H+ ions from the blood and prevent the pH from rising too much.

Option A, carbon dioxide, is involved in the buffering system through its conversion to carbonic acid.

However, it does not directly donate H+ ions to act as a buffer when blood pH rises.

Option B, carbon monoxide, is a toxic gas that binds to hemoglobin in red blood cells, preventing them from carrying oxygen.

It is not involved in the buffering system and does not donate H+ ions.

Option D, oxygen, is carried by hemoglobin in red blood cells and is essential for respiration.

It is not involved in the buffering system and does not donate H+ ions.

Triple covalent bonds.

Nitrogen gas (N2) is an extremely stable molecule because it consists of two nitrogen atoms bonded together by a triple covalent bond.

A covalent bond is a type of chemical bond where atoms share electrons to form a molecule.

In a triple covalent bond, three pairs of electrons are shared between the two atoms, resulting in a very strong bond that makes the molecule extremely stable.

Choice A.

Ionic bonds is not correct because ionic bonds involve the transfer of electrons from one atom to another to form ions, which are then attracted to each other due to their opposite charges.

Nitrogen gas does not contain ions and is not held together by ionic bonds.

Choice B.

Hydrogen bonds is not correct because hydrogen bonds are weak electrostatic attractions between molecules that contain hydrogen atoms bonded to highly electronegative atoms such as oxygen or nitrogen.

Nitrogen gas does not contain hydrogen atoms and is not held together by hydrogen bonds.

Choice C.

Resonance bonds is not correct because resonance refers to the delocalization of electrons in a molecule where multiple Lewis structures can be drawn to represent the molecule.

Nitrogen gas has a single Lewis structure and does not exhibit resonance.

The cell membrane is present in both prokaryotic and eukaryotic cells.

The cell membrane is a thin, flexible barrier that surrounds all cells and separates the inside of the cell from the outside environment.

It is composed of a lipid bilayer and regulates the movement of substances into and out of the cell.

Choice B is incorrect because the Golgi apparatus is not present in prokaryotic cells.

The Golgi apparatus is an organelle found in eukaryotic cells that is involved in modifying, sorting, and packaging proteins and lipids for transport to other parts of the cell or to be secreted outside the cell.

Choice C is incorrect because chloroplasts are not present in prokaryotic cells.

Chloroplasts are organelles found in plant cells and some algae that are responsible for photosynthesis.

Choice D is incorrect because the endoplasmic reticulum is not present in prokaryotic cells.

The endoplasmic reticulum is an organelle found in eukaryotic cells that is involved in protein synthesis and lipid metabolism.