A human hair is about 50 um thick. A pet flea is about 1 mm in size. How

many times smaller is the thickness of a human hair than a flea?

Calculate the number of moles of Zn (NO3) 2 in 131.50 g of this substance. Note that the formula weight of Zn (NO3) 2 is 189.40 amu.

What process is aided by lightning legumes and soul bacteria

Write one to two paragraphs аbout: What is the relationship between the atomic numbers and ionic radii of the elements in group 1? What is the relationship between atomic numbers and first ionization energies?

What effect would an isotonic solution have on the egg?

Calculate the work done by the expansion of hydrogen gas when 7.1 g of sodium react with water at constant temperature of 27°C and pressure of 1.7 atm. Use a precision of 2 significant digits. 2Na (s) + 2H2O (l) → 2NaOH (s) + H2 (g)

Which element is the least metallic between cadmium, silver, zinc, or iron?

Describe the motion of molecules in an ice cube an in a radiator in winter

True or False. Heat is always transferred from warmer objects to cooler objects.

Which of the following statements is true? Question 5 options: Nuclear decay rates vary with the conditions of the reaction, but chemical reaction rates do not.

In which group is an element that has an outer-level electron configuration consisting of one electron in the nd orbital and two electrons in the ns orbital?