Answer:
6.25 μg/mL
Explanation:
When a dilution is made, the mass of the solute is conserved (Lavoiser's law), so the mass pipetted will be the mass in the assay. The mass is the concentration (C) multiplied by the volume (V). If the pipet solution is called 1, and the assay 2:
m1 = m2
C1*V1 = C2*V2
C1 = 250 μg/mL
V1 = 25 μL
V2 = 975 μL + 25 μL = 1000 μL (is the final volume of the assay after the addition of LDH)
250*25 = C2*1000
C2 = 6.25 μg/mL
Answer:
Lose two electrons.
Explanation:
Barium is present in group 2.
It is alkaline earth metal.
Its atomic number is 56.
Its electronic configuration is Ba₅₆ = [Xe] 6s².
In order to attain the noble gas electronic configuration it must loses its two valance electrons.
When barium loses it two electron its electronic configuration will equal to the Xenon.
The atomic number of xenon is 54 so barium must loses two electrons to becomes equal to the xenon.
Explanation:
1.
Given parameters:
Frequency of the radiation = 8.4 x 10¹⁴Hz
Unknown:
Energy of the wave = ?
Solution:
The energy of a wave is given by the expression below;
E = hf
E is the energy
h is the Planck's constant = 6.63 x 10⁻³⁴m²kg/s
f is the frequency
Now insert the parameters and solve;
E = 6.63 x 10⁻³⁴m²kg/s x 8.4 x 10¹⁴Hz
E = 5.57 x 10¹ x 10⁻²⁰J
E = 5.57 x 10⁻¹⁹J
2.
Given parameters:
Wavelength = 2.13 x 10⁻¹³m
Unknown:
Frequency of the wave = ?
Solution:
The frequency of a wave can be determined using the expression;
C = f∧
C is the speed of light = 3 x 10⁸m/s
f is the frequency
∧ is the wavelength
f = = = 1.41 x 10²¹hz
Answer:
See below
Explanation:
Molecular formula ( just write down all of the elements ) C 4 H4 O4
Empiracle formual CHO
"Molecular formulas tell you how many atoms of each element are in a compound, and empirical formulas tell you the simplest or most reduced ratio of elements in a compound"