A structural component is fabricated from an alloy that has a plane-strain fracture toughness of 50 MPa√m. It has been determined that this component fails at a stress of 225 MPa when the maximum length of a surface crack is 1.2 mm. What is the maximum allowable internal crack length (in mm) without fracture for this same component exposed to a stress of 225 MPa and made from another alloy that has a plane strain fracture toughness of 30 MPa√m ?

1. 1 mole of anything contains 6.022x10^23 pieces  

d  

2. a  

3. c, number  

5. 1.24x10^24atoms / 6.022x10^23atoms/mole = 2moles h2 atoms  

6. fe2br3 mass = 2moles x mass fe + 3 moles x mass br  

molar mass = grams / number of moles = g/mole  

to find moles = g / molar mass  

to find mass = g = molar mass / moles

2h2o2--> 2h2o + o2

this reaction is of the spontaneous decomposition of hydrogen peroxide down into water and oxygen.

add 2 molecules of hydrogen peroxide and 2 molecules of water. since oxygen is naturally diatomic, the total number of atoms of each element is now the same on both sides of the equation so it is balanced.

this may not be entirely correct but let me know.

answer7,570,82356 cubic centimeters;