Lead glass contains 18-40% by mass of pbo (instead of cao in regular glass). lead glass is still used industrially, but lead crystal drinking goblets are no longer considered safe, as the lead may leach out and cause toxic responses in humans. a particular 286-g lead crystal goblet that holds 550 ml of liquid is 19 % pbo by mass, and it leaches 4.2 micrograms of lead every time it is filled.

What is the number of moles of chemical units represented by 9.03x10^24? and how do i show work? (dumb it down )

Why is the bond angle in a water molecule less than the bond angle of methane? a. the central oxygen atom in water has two lone pairs of electrons, whereas the central carbon atom in methane has no lone pairs. b. the central hydrogen atom in water has one lone pair of electrons, whereas the central carbon atom in methane has two lone pairs. c. the central oxygen atom in water has four lone pairs of electrons, whereas the central carbon atom in methane has only one lone pair. d. the central oxygen atom exerts more repulsive force on surrounding atoms than the central carbon atom in methane does. reset next

Rocks, as they are compressed, begin forming mountains above the earth's surface when two continental plates converge. the continental crust increases in depth as the mountains grow above. the himalayan mountains formed at a convergent plate boundary in this manner. the rocks are smashed together causing them to due to the intense heat and pressure from the colliding plates and eventually forming rock. a) melt; igneous b) layer; sedimentary c) recrystallize; metamorphic d) melt into the earth's interior; metamorphic