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
Answer: has zero mass
is an electron
has a -1 charge
is electromagnetic energy
Explanation:
A beta-particle is an electron emitted from the nucleus of an atom following the decay of a neutron into a proton. Beta rays are deflected by a magnetic field in a direction that indicates a negative charge, thus they are electromagnetic in nature.
The beta particle released is basically a electron with -1 charge and no mass.
General representation of beta particle in the form of 
given as 
where,
Z represents Atomic number
A represents Mass number
X represents the symbol of an element
The correct answer would be <span>0.22 N.
Hope this helps.</span>
A neutron has a charge of 0, as it is neutral.
The jewelry is submerged in the graduated cylinder, the total volume increased to 61.2 ml mass of the water in the graduated cylinder is 128.5 gram.
<h3>What is density?</h3>
Density is a amount of a substance per unit area of the volume of the mass and it is the ratio of mass and the volume unit is centimeter cube.
The density of the substance = mass / volume
substituting the value in the equation,
Density = 132.6 / 48.6 = 2.1 centimeter cube.
mass = density volume
mass = 2.1 61.2
mass = 128.5 gram.
Therefore, mass of the water in the graduated cylinder is 128.5 gram if jewelry is submerged in the graduated cylinder, the total volume increased to 61.2 ml.
Learn more about density, here:
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