Which statement is true?

a

Atoms can be changed

b

All atom are not stable

c

Atoms can never be changed

d

Both A and B

What are Example of alkalis?

A scientist performs an experiment in which they create an artificial cell with a selectively permeable membrane through which only water can pass. They inject a 5 M solution of glucose into the cell and then place the cell into a beaker of water.

Interstellar space (the space between the stars) is filled with extremely low-density hydrogen gas. In the vicinity of a hot star, this gas can be heated to a very high temperature. This hot, low-density gas will

Which of these molecules has the same number of shared electron pairs as unshared electron pairs? (a) hcl, (b) h2s, (c) pf3, (d) ccl2f2 (e) br2?

Chlorine atoms each have 17 protons. How many neutrons does each Cl-37 atom have? A. 17 B. 20 C. 37 D. 54

Density is not a physical property of mass. True False

Does skin have a nucleus true or false

Bacteria are only found in decaying matter. A. True B. False

Which is considered a chemical mutagen? tanning beds tobacco X-rays precious metals

Combining 0.380 mol Fe2O3 with excess carbon produced 13.7 g Fe Fe2O3 + 3C → 2Fe + 3CO What is the actual yield of iron in moles? What is the theoretical yield of iron in moles? What is the percent yield?