The thikness of an eye lash is 15 mm how much this will be in meters ? write it in scientific Notation. Distance between Los Angeles and Mexico City is 2491 kilometers (1548 miles).
Write those 2 numbers into scientific Notation

Answer

1.5x10^-3 m

24.91x10^5

Explanation:

15 millimeters

- 1 mm = .0015

exponent indicates which way the decimal moved and to how many places

we moved the decimal backwards (negative) 3 spaces

2491 km= 2491000 m

exponent indicates which way the decimal moved and to how many places

we moved the decimal forwards (positive) 5 spaces

2491000.00 --> 24.91000

the number of valence electrons for each molecule or ion is shown beneath the structure. remember hydrogen will not have more than two electrons. this hydrogen is part of a covalent bond (sharing two electrons). a double bond here would cause hydrogen to share four electrons with phosphorus.

as given the equation is

2al + 6 hcl > 2 alcl3 + 3 h2(g)

as per equation two moles of aluminum reacts with six moles of hcl to give two moles of alcl3 and three moles of hydrogen gas

given: three moles of al are present and 7 moles of hcl

for three moles of aluminum nine moles of hcl will be required

however as 7 moles of hcl are present so the limiting reagent is hcl

hcl is going to decide the number of moles of product formed

when six moles of hcl are present = 3 moles of h2 are formed

when one mole of hcl is present == 3/6 mole sof h2 will be formed

when 7 moles of hcl are present = 3 x 7/ 6 moles of h2 will be formed = 3.5 moles of h2