Nokea
Which two types of elements are most likely to form an ionic bond?
- A. Two elements that are in the same period.
- B. Two elements that are non-metals and have p orbitals.
- C. One element that is a transition metal with d orbitals and one element that is a metal with s orbitals.
- D. One element that is a metal with s orbitals and one element that is a nonmetal with p orbitals.
Correct Answer: D
Rationale: Ionic bonds typically form between a metal, which donates electrons from its s orbital, and a nonmetal, which accepts electrons into its p orbital. This transfer of electrons leads to the formation of an ionic bond. Choice A is incorrect as elements in the same period may vary significantly in their properties. Choice B is incorrect because ionic bonds are usually formed between a metal and a nonmetal, not two nonmetals. Choice C is incorrect because transition metals generally form complex ions through the sharing of electrons, not typical ionic bonds.
You may also like to solve these questions
What is the structure and function of elastic arteries?
- A. They are the smallest arteries and constrict and dilate frequently.
- B. They are medium-sized arteries that distribute blood to various organs.
- C. They are the largest arteries and stretch and recoil to accommodate blood pressure changes.
- D. They are thin-walled arteries that supply blood to the capillaries.
Correct Answer: C
Rationale: The corrected answer is C. Elastic arteries, like the aorta, are the largest arteries in the body. They possess elastic fibers in their walls, allowing them to stretch and recoil in response to the pulsatile nature of blood flow from the heart. This elasticity helps to maintain blood pressure by absorbing the pressure waves generated by the heart's contractions and ensuring continuous blood flow to the organs. Choices A, B, and D are incorrect because elastic arteries are not the smallest arteries, do not constrict and dilate frequently, are not medium-sized arteries for distributing blood to various organs, and are not thin-walled arteries supplying blood to capillaries. Elastic arteries have a specific structure and function related to their ability to accommodate blood pressure changes due to their elastic properties, which is essential for the cardiovascular system's proper functioning.
What is the muscular tube that connects the outer surface to the cervix in a woman's birth canal referred to as?
- A. The uterus
- B. The cervix
- C. The vagina
- D. The ovaries
Correct Answer: C
Rationale: The correct answer is C, 'The vagina.' The muscular tube that connects the outer surface to the cervix in a woman's birth canal is called the vagina. The vagina serves as the passageway for menstrual flow, sexual intercourse, and childbirth. The cervix, not the uterus, connects the vagina to the uterus. The ovaries, on the other hand, are the organs responsible for producing eggs and female hormones, but they are not the muscular tube connecting the outer surface to the cervix in the birth canal.
Which of the following compounds often contains a carboxyl group?
- A. Carbohydrates
- B. Glycolipids
- C. Amino Acids
- D. DNA
Correct Answer: C
Rationale: The correct answer is C: Amino Acids. Amino acids, the building blocks of proteins, contain both an amine group and a carboxyl group. The carboxyl group (-COOH) is crucial for the structure and function of proteins as it participates in peptide bond formation. Carbohydrates and DNA do not typically contain carboxyl groups as a functional group. Glycolipids consist of a carbohydrate chain linked to a lipid, but they do not inherently contain a carboxyl group.
Which of the following organs is part of the central nervous system?
- A. Heart
- B. Brain
- C. Liver
- D. Lungs
Correct Answer: B
Rationale: The correct answer is B: Brain. The brain is a vital organ that is part of the central nervous system, along with the spinal cord. It plays a crucial role in processing information, controlling body functions, and coordinating responses to stimuli. The heart, liver, and lungs are not part of the central nervous system; they belong to the cardiovascular and respiratory systems, respectively. The heart is part of the cardiovascular system, responsible for pumping blood throughout the body. The liver is part of the digestive system, involved in processes like detoxification and metabolism. The lungs are part of the respiratory system, facilitating the exchange of oxygen and carbon dioxide during breathing.
Which statement about white blood cells is true?
- A. B cells are responsible for antibody production.
- B. White blood cells are produced in the bone marrow before entering the bloodstream.
- C. Platelets, a specialized class of blood cells, function to clot blood and stop bleeding.
- D. The majority of white blood cells are active throughout life, providing immunity across all age groups.
Correct Answer: A
Rationale: The correct answer is A: B cells, a type of white blood cell, are responsible for producing antibodies in response to pathogens. Antibodies play a crucial role in identifying and neutralizing foreign substances like bacteria and viruses in the body, aiding in the immune response and protecting against infections. This function is essential for maintaining a healthy immune system. White blood cells, including B cells, are produced in the bone marrow before entering the bloodstream. Platelets, not white blood cells, are a specialized class of blood cells that function to clot blood and stop bleeding. While white blood cells provide immunity, not all of them are active throughout life as some have specific lifespans and functions.