We know that the source of a sound wave is a vibrating

Physics for Scientists and Engineers with Modern Physics 9
Why is the following situation impossible? In the Bohr model of the hydrogen atom, an electron moves in a circular orbit about a proton. The model states that the electron can exist only in certain allowed orbits around the proton: those whose radius r satisfies r 5 n2 (0.052 9 nm), where n 5 1, 2, 3

Macroeconomics 22nd
Why is a quota more detrimental to an economy than a tariff that results in the same level of imports as the quota? What is the net outcome of either tariffs or quotas for the world economy?

Concepts of Biology 1
Magnesium has an atomic number of 12. Which of the following statements is true of a neutral magnesium atom? a. It has 12 protons, 12 electrons, and 12 neutrons. b. It has 12 protons, 12 electrons, and six neutrons. c. It has six protons, six electrons, and no neutrons. d. It has six protons, six ele

Campbell Biology in Focus 2
In what way do the membranes of a eukaryotic cell vary? (A) Phospholipids are found only in certain membranes. (B) Certain proteins are unique to each kind of membrane. (C) Only certain membranes of the cell are selectively permeable. (D) Only certain membranes are constructed from amphipathic mo

Concepts of Biology 1
Figure 18.12 Which of the following statements about the male reproductive system is false? a. The vas deferens carries sperm from the testes to the seminal vesicles. b. The ejaculatory duct joins the urethra. c. Both the prostate and the bulbourethral glands produce components of the semen. d. Th

Biology 2e by Openstax
Figure 32.3 If the anther is missing, what type of reproductive structure will the flower be unable to produce? What term is used to describe an incomplete flower lacking the androecium? What term describes an incomplete flower lacking a gynoecium? Figure 32.3 The four main parts of the flower a

Chemistry for today : general, organic, and biochemistry 9
Most of the remaining water in washed laboratory glassware can be removed by rinsing the glassware with acetone (propanone). Explain how this process works (acetone is much more volatile than water).

Biochemistry 9
(a) The major energy storage compound of animals is fats (except in muscles). Why would this be advantageous? (b) Why dont plants use fats/oils as their major energy storage