Hello.
The answer is: A. keep a cork in the test tube so the solution cannot spill out
B and C both could be very deadly and it shouldnt be D because if u have an open flame you shouldnt open it even if its not towards anyone.
have a nice day
<span>'It is formed when metal atoms lose electrons to nonmetal atoms' is the incorrect statement. This statement is the definition of ionic bonding.
Hope this helps!</span>
Since the comb is positively charged, the hair will stick to the comb.
I think
Answer: Total pressure inside of a vessel is 0.908 atm
Explanation:
According to Dalton's law, the total pressure is the sum of individual partial pressures. exerted by each gas alone.

= partial pressure of nitrogen = 0.256 atm
= partial pressure of helium = 203 mm Hg = 0.267 atm (760mmHg=1atm)
= partial pressure of hydrogen =39.0 kPa = 0.385 atm (1kPa=0.00987 atm)
Thus 
=0.256atm+0.267atm+0.385atm =0.908atm
Thus total pressure (in atm) inside of a vessel is 0.908
Answer:
(a) 
(b) Rubidium
Explanation:
Hello,
This titration is carried out by assuming that the volume of base doesn't have a significant change when the mass is added, thus, we state the following data a apply the down below formula to compute the molarity of the base solution:

Solving for the molarity of base we've got:

Now, we can compute the moles of the base as:

(a) Now, one divides the provided mass over the previously computed moles to get the molecular mass of the unknown base:

(b) Subtracting the atomic mass of oxygen and hydrogen, the metal's atomic mass turns out into:

So, that atomic mass dovetails to the Rubidium's atomic mass.
Best regards.