Answer: A balance is used to determine accurate mass of substances.
Explanation: Electronic balance is used to measure the small to large mass of substance from miligrams to grams to kilograms according to their features. Differnt different Electronic balances are used on the basis of amount to be measure.
In pharmaceuticals , other laboratories , schools , colleges mainly electronic balance is used , as it measure accurate weight of the substances.
b. 1s22s22p4
c. 1s22s22p5
d. 1s22s22p63s23p2
Your answer would be A.
Answer:
Pb(NO3)2 + 2NaCl = PbCl2 + 2NaNO3
Explanation:
Lead nitrate is Pb(NO3)2
Sodium Chloride is NaCl
The basic reaction is:
Pb(NO3)2 + NaCl = PbCl2 + NaNO3
Now we need to balance the equation. Note that the lead nitrate contributes 2 (NO3) units, but there is only 1 NO3 on the product side. So start by adding a second NaNO3:
Pb(NO3)2 + NaCl = PbCl2 + 2NaNO3
Now we have 2 Na atoms on the right side, so add a "2" to the NaCl:
Pb(NO3)2 + 2NaCl = PbCl2 + 2NaNO3
This is starting to look good. Lets check the atom/unit counts on both sides of the equation:
Reactants Products
Pb 1 1
NO3 2 2
Na 2 2
Cl 2 2
The equation is now balanced. Pb(NO3)2 + 2NaCl = PbCl2 + 2NaNO3
B. Elements produce continuous spectra.
C. Elements produce spectra with only a few distinct lines.
Atomic emission spectra are unique to each element and consist of distinct lines representing different energy levels.
The correct statement regarding atomic emission spectra is option C: Elements produce spectra with only a few distinct lines.
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(2) artificial transmutation
(3) nuclear fusion
(4) nuclear fission