Diagram is on the picture below.
Answer is: 1).
Sodium chloride is ionic compound and in the water dissociate in sodium cation (positive charge) and chloride anion (negative charge). Water is polar compound, oxagan has negative charge and hydrogen charge. Positive interact witn negative charge and negative with positive charge.
Answer:

Explanation:
A radioactive isotope is an isotope that undergoes nuclear decay, breaking apart into a smaller nucleus and emitting radiation during the process.
The half-life of an isotope is the amount of time it takes for a certain quantity of a radioactive isotope to halve.
For a radioactive isotope, the amount of substance left after a certain time t is:
(1)
where
is the mass of the substance at time t = 0
m(t) is the mass of the substance at time t
is the half-life of the isotope
In this problem, the isotope is uranium-235, which has a half-life of

We also know that the amount of uranium left in the rock sample is 6.25% of its original value, this means that

Substituting into (1) and solving for t, we can find how much time has passed:

Answer:
40/18AR
Explanation:
sorry my answer was late but i hope this helps someone else! I got it right on the test
Answer:

Explanation:
(a) Hybridization of orbitals
See the Lewis structure of propyne in the first diagram below.
C1 is directly bonded to two other atoms (H and C2) so it is sp hybridized.
C2 is directly bonded to two other atoms (C1 and C3) so it is sp hybridized.
C3 is directly bonded to four other atoms (C2 and 3 H) so it is sp³ hybridized.
(b) C2-C3 Sigma Bond
See the atomic and molecular orbitals in the second picture below.
C3 is using its hybrid atomic orbitals to form sigma molecular bonds. The C2-C3 sigma bond is formed by the overlap of the C2 sp atomic orbital with the C3 sp³ atomic orbital to make a σ(sp-sp³) molecular orbital.
(c) Bond angles
C1 and C2 are sp hybridized. Since the angle between sp orbitals is 180°, all atoms directly attached the C1 and C2 must be in a straight line. The C-C-C bond angle is 180°.
<span>The noble gases are the six elements that make up Group 18 of theperiodic table: helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn). At one time, this family of elements was also known as the rare gases.</span>