I would he would try to enter as the tide is rising, and leave as the tide is falling. Those things happen at all different times of day during a month. Hope it helps!!
To find pH, use the following formula ---> pH= - log [H+]
so first we need to calculate the [H+] concentration using the OH concentration. to do this, we need to use this formula--> 1.0x10-14= [H+] X [OH-], so we solve for H+ and plug in
[H+]= 1.0X10-14/[OH-]---> 1.0 x 10-14/ 1.0 x 10-4= 1.0 x 10-10
now that we have the H+ concentration, we can solve of pH
pH= -log (1.0x10-10)= 10
answer is A
H₂SO₄:
V=0,95L
Cm=0,420mol/L
n = CmV = 0,42mol/L * 0,95L = 0,399mol
KOH:
V=0,9L
Cm=0,26mol/L
n = CmV = 0,26mol/L * 0,9L = 0,234mol
H₂SO₄ + 2KOH ⇒ K₂SO₄ + 2H₂O
1mol : 2mol
0,399mol : 0,234mol
limiting reagent
reamins: 0,399mol - 0,117mol = 0,282mol
n = 0,282mol
V = 0,950L + 0,900L = 1,85L
Cm = n / V = 0,282mol / 1,85L ≈ 0,152M
Add proton + neutrons = Mass 37
Proton is same as your atomic mass= 17
If you go on the periodic table look up 17 and it will give u the letter.
Usually (ignoring transition metals, as they kinda get trickier), the element's valency can be found out by its group (column) number. Usually, we ignore the transition metal block while counting these columns, so Aluminium is in group 3, for example. Since Aluminium is in group 3, it has 3 valence electrons.
