The diffusion of molecules into a cell can be modelled by using agar cubes infused with phenolphthalein indicator and soaked in sodium hydroxide (NaOH). Phenolphthalein turns a pink color when in the presence of a base. As the NaOH diffuses into the agar, the phenolphthalein changes to pink and thus indicates how far the NaOH has diffused into the agar. By cuttting an agar block into cubes and various sizes, it is possible to show the effect of cell size on diffusion

Apreschooler with partial-thickness burns on 21% of the total body surface area progresses from the emergency phase to the acute phase of burn care. what is the most important nursing intervention at this time?

Every compound can be represented by a chemical formula. a chemical formula is the set of symbols showing the elements that make up a compound and their proportions. water’s chemical formula is h 2 2 o. that means a molecule of water contains two atoms of hydrogen and one atom of oxygen chemically bonded. a molecule is a group of two or more atoms bonded together. molecules can range in size from two to thousands of atoms. a molecule of a compound is the smallest unit of that compound. every molecule of water has all the physical and chemical properties of water. that’s because every molecule of water is made of the same elements in the same proportions: two hydrogen atoms and one oxygen! which of the following is a true statement? a every molecule of the same compound will have different properties. b every molecule of a compound has the same proportion of elements. c molecules can be physically separated into smaller units of a compound. d molecules cannot be represented by chemical formulae.

Populations of blue-winged warblers, a type of bird, migrate south in the winter and return to canadian breeding grounds in the spring. as global temperatures have increased due to climate change, spring has started arriving in the warbler's breeding grounds earlier in the year, before the warblers return. warblers now arrive at their breeding grounds too late to select ideal nesting sites and to feed on important early-spring food sources how are populations of blue-winged warblers most likely to be affected by the earlier arrival of spring? o a. populations will go extinct since the warblers will stop migrating to breeding grounds. b. populations will be unaffected since most species can quickly adapt to effects of climate change. c. populations will increase since warmer temperatures are generally beneficial to survival, d. populations will decline since individuals will be less likely to successfully reproduce, reset next