Using the equation pH= -log [H+], a solution with a [H+]= 10-9 M has a pH of which of the following?

When a proton is emitted from the nucleus of an atom, the atomic number (Z) decreases by 1 because a proton has a positive charge, and it's effectively removing one positive charge from the nucleus. However, the atomic mass (A) remains the same because protons and neutrons contribute to the atomic mass, and the emission of a proton does not affect the number of neutrons.

The correct answer is A. Browning of an apple is often caused by enzymes such as polyphenol oxidase. Lemon juice has a low pH, creating an acidic environment that inhibits the activity of these enzymes and prevents browning.

The hip bone (or pelvis) in adults is formed by the fusion of three separate bones: the ilium, ischium, and pubis. This fusion occurs during adolescence and results in a single, solid structure.

The correct answer is B. Fertilization typically occurs in the fallopian tube, where the sperm can meet and fertilize the egg. The fertilized egg then travels to the uterus for implantation and development.

The correct answer is B. This option involves a control group (water) and an experimental group (energy drink) to compare the effects. By having a group that does not consume the energy drink, researchers can better attribute any observed differences in running speed to the energy drink itself.

The correct answer is B. The vermiform appendix is a small, tube-like structure that extends from the cecum, which is the first part of the large intestine. It is not associated with the jejunum, rectum, or ischium.

The correct answer is B. Objects A and B have the same mass, but B falls faster because it has less air resistance. Objects C and D have different masses, but C falls faster because it has a higher mass-to-surface-area ratio, which reduces the effect of air resistance.

The correct answer is B. When a volcano erupts, it releases built-up pressure and gases, similar to the fizzing of a can of soda when opened. Both involve the release of pressure and trapped substances, leading to an outward expulsion of materials.

The correct answer is C. The digestive system is responsible for breaking down complex food molecules, including proteins, into simpler components such as amino acids that can be absorbed and utilized by the body.

The correct answer is A. Melanocytes are responsible for producing the pigment melanin and transferring pigment granules to adjacent epidermal cells, particularly keratinocytes. This process contributes to the coloration of the skin.