Most people like to go outside on a sunny day, but too much sun exposure can cause sunburns as well as long term health problems, such as eye damage or skin cancer. How do humans protect themselves from too much sun exposure?

What is the five part definition for an object to be considered a mineral

2C2H2 + 5 O2 → 4CO2 + 2H2O Use the given standard enthalpies of formation to calculate ∆H for this reaction C2H2 = 227.4 CO2 = - 393.5 H2O = - 241.8 1256.2 kJ b. - 1256.2 kJ c. - 2512.4 kJ d. 2512.4 kJ

a solution of household vinegar is to be analyzed. A pipet is used to measure out 10 ml of the vinegar which is placed in a 250ml volumetric flask.

Find the pH of the 0.169 M NaOH solution in problem 4 (assume that the NaOH dissociates completely into Na and OH-) and its associated absolute uncertainty by propagating the uncertainty in concentration found in part b of the problem.

Which of the following cell structures exhibits selective permeability between a cell and its external environment?

In the synthesis reaction, the white powder produced is magnesium oxide (mgo, mm = 40.3 g/mol). how many moles of magnesium oxide were formed (number of moles = mass (g) / molar mass (g/mol)) ? choose the closest answer. a. 0.21 moles b. 0.

Which of the following is the most likeley example of an favorable mutation A. A mutation that makes a rabbit able run faster B. A mutation that changes the rabbit's fur to bright orange C. A mutation that changes the color of the rabbit's eyes D.

Which of these mole ratios is possible for this reaction? FeCl3 + 3NaOH → Fe (OH) 3 + 3NaCl 1:1 1:3 3:1 2:3

The chemical equation for reduction of phosphorite Ca3 (PO4) 2

Synthesize What environmental effects are shared by all fossil fuels?