<span>D. The screw changes the direction of a force - it converts linear force into rotational force. It also reduces the force required - the closer the threads, the smaller the input force required to get the same output force.</span>
Answer:
Rb+
Explanation:
Since they are telling us that the equivalence point was reached after 17.0 mL of 2.5 M HCl were added , we can calculate the number of moles of HCl which neutralized our unknown hydroxide.
Now all the choices for the metal cation are monovalent, therefore the general formula for our unknown is XOH and we know the reaction is 1 equivalent acid to 1 equivalent base. Thus we have the number of moles, n, of XOH and from the relation n = M/MW we can calculate the molecular weight of XOH.
Thus our calculations are:
V = 17.0 mL x 1 L / 1000 mL = 0.017 L
2.5 M HCl x 0.017 L = 2.5 mol/ L x 0.017 L = 0.0425 mol
0.0425 mol = 4.36 g/ MW XOH
MW of XOH = (atomic weight of X + 16 + 1)
so solving the above equation we get:
0.0425 = 4.36 / (X + 17 )
0.7225 +0.0425X = 4.36
0.0425X = 4.36 -0.7225 = 3.6375
X = 3.6375/0.0425 = 85.59
The unknown alkali is Rb which has an atomic weight of 85.47 g/mol
Hi!
The answer is breathing.
Protozoans are organisms that can multiply themselves in humans, and serious infections can develop from one organism. The most frequently transmission methods are contaminated food or fecal contact. Dog bites inoculate bacteria into deep tissue, and they also serve as a transmission method.
Breathing is not considered to be likely to transmit protozoan infection because protozoans rarely develop in the respiratory tract.
Answer:
.5 gm / ml
Explanation:
Density is defined as mass/ volume
so density of this substance is 5 gm / 10 ml = .5 gm/ ml
[k]+ [:CL:] -
k has no dots and CL had 8 so 2 on each side of CL and then CL is negative after the closed brackets
