Answer: Potential energy is converted to kinetic energy and back again.
Explanation:At points 1 and 3, the pendulum stops moving, and its mechanical energy is purely potential. At point 2, the pendulum is moving the fastest, and its mechanical energy is purely kinetic. Therefore, as the pendulum moves from point 1 to point 3, its potential energy is first converted to kinetic energy, then back to potential.
Answer:
PBr5 is the formula of phosphorus pentabromide.
hope it helps!
Answer:
(C) through the atmosphere
Explanation:
Answer:
A. there is an isotope of lanthanum with an atomic mass of 138.9
Explanation:
By knowing the different atomic masses of both Lanthanum atoms, we can not tell anything about their occurence in nature. Therefore, all the last three options are incorrect. Because, the atomic mass does not tell anything about the availability or natural abundance of an element.
Now, the isotopes of an element are those elements, which have same number of electrons and protons as the original element, but different number of neutrons. Therefore, they have same atomic number but, different atomic weight or atomic masses.
Hence, by looking at an elements having same atomic number, but different atomic masses, we can identify them as isotopes.
Thus, the correct option is:
<u>A. there is an isotope of lanthanum with an atomic mass of 138.9.</u>
Answer:
Brainliest pls
Explanation:
1 mole of a substance contains Avagadro’s number of particles,
i.e. 6.023*10^23
By unitary method,
5 moles of oxygen contains 5 times the Avagadro’s number of particles
i.e. 5* (6.023*10^23) = 3.0115*10^24 number of particles.
Now, the further answer depends on what particles the question concentrates on.
If number of atoms are asked , the above answer must be multiplied by 2, because oxygen is a diatomic gas and each atom contributes to be a particle.
therefore, 5 moles of oxygen has 6.023*10^24 atoms.
If number of molecules asked, the above answer is directly written...
