Answer:
7.5 pounds per square-inch
At sea level, one square-inch of any surface has about 15 pounds of air sitting on top of it. At 18,000 feet, that same square inch has only 7.5 pounds per square-inch (psi) exerted on it.
<span>Kelly has some sand in a bucket, but she thinks that there may be some salt mixed in with her sand. How can she determine if there is salt in the sand?</span><span>
Answer: If she puts water in the bucket, the salt will dissolve.
Hope This Helped! :3</span>
the correct answer is A.
Each atom has three sub particles, which are electron, proton and neutron. To get the atomic mass for each atom, one has to add the masses of the proton, neutron and electron in an atom. For each atom, the major contributors to its mass are proton and neutron, this is because the mass of the electron is very small indeed. Thus, the atomic mass of an element is usually in the range of its mass number, which is obtained by the summation of proton and neutron. Since it is the number of proton that indicate an atomic number and it is the mass number that indicate atomic mass, therefore, atomic mass can be greater than the atomic number.
Answer:
Actinium is a chemical element with the symbol Ac and atomic number 89. A soft, silvery-white radioactive metal, actinium reacts rapidly with oxygen and moisture in air forming a white coating of actinium oxide that prevents further oxidation.
