We're told oxygen is the most common element in the Earth's solid crust. But how much oxygen is there? Let's compare to the amount of oxygen in the Earth's atmosphere, like this: The most common minerals in the Earth's crust are feldspars, and anorthite (CaAl2Si2O8) is a typical feldspar. Let's assume the entire crust is made of anorthite, with a density of 2.8 g/cm .
The radius of the Earth is 6371. km and let's say the trust is the upper 100 km of it.
Let's model the Earth's atmosphere as a layer on top of the Earth about 100 km thick with an average density of 0.99 g/m, and which is 23.1% oxygen by mass.
Use this information to calculate the ratio of the mass of oxygen in the Earth's atmosphere to the mass of oxygen in the Earth's crust. Round your answer to 2 significant digits X 5 ?

3) in peaches, [oh]=3.16x10-11 m a) find [h+ ] b) what is the ph? c) is the solution acidic, basic, or neutral?

Electromagnets coils of wire paper clips picked up 10 3 15 6 20 9 25 12 ms. owens' class was studying magnets. ms. owens showed her students how to make an electromagnet using a nail, a d-cell battery, and plastic coated wire. the students wrapped the wire around the nail and then attached the ends to the battery. when they were finished, they tested their magnets by investigating how many paperclips their magnets could pick up. they also tested whether they could increase the strength of their electromagnets by using more coils of wire. they recorded the class average of their results in the data table seen here. ms. owens asked her students to graph their data in a line graph. how should the students label the x-axis on their line graph? a) size of battery b) number of paper clips c) number of coils of wire d) strength of electromagnet

Two liquids are poured into a beaker. after a few seconds, the beaker becomes warm. which of the following best describes this reaction? a. an exothermic reaction b. a decomposition reaction c. an endothermic reaction d. a single-displacement reaction