Answer:
d) Cr⁺³
Explanation:
Consideremos un ion que contiene 24 protones, 28 neutrones y 21 electrones.
Para encontrar el simbolo del elemento, tenemos que considerar el número atómico (Z) que es igual al número de protones. Con esta información, buscamos en la tabla periódica el elemento con Z=24 es el Cromo.
La carga total está dada por la diferencia entre protones y electrones. Los ´protones tienen carga +1 y los electrones carga -1. Luego, este ion tiene carga:
24 protones + 21 electrones = 24 . (1) + 21 . (-1) = +3
El simbolo del ion es Cr⁺³.
Electron structure of sodium:
₁₁Na: 1s²2s²2p⁶3s¹
Answer:
1) chemical indicators won't work above it's pH range so therefore it probably won't change colour.
2) the solution should be clear and colourless to see colour change.
3) indicators tend to be of low accuracy so it's not 100% reliable.
The elements in each group have the same number of electrons in the outer orbital. Or also called valence electrons. Khan academy has a great video online explaining why this happens. (It only happens for main group elements). Here is a link (sorry you can’t click it in Brainly) https://www.khanacademy.org/science/chemistry/periodic-table/copy-of-periodic-table-of-elements/v/periodic-table-valence-electrons. Feel free to message me for a better explanation, I would explain now but I’m not sure how much you know about this. If you know how to write an electron configuration you can see how all the electron configurations for the same group (not the transitional metals only the main groups) have the same number of valence electrons. I hope that helped, sorry I was vague about the explanation :)
Answer:
THE EMPIRICAL FORMULA OF THE SUBSTANCE IS C2H5NO
Explanation:
The steps involved in calculating the empirical formula of this substance in shown in the table below:
Element Carbon Hydrogen Nitrogen Oxygen
1. % Composition 40.66 8.53 23.72 27.09
2. Mole ratio =
%mass/ atomic mass 40.66/12 8.53/1 23.72/14 27.09/16
= 3.3883 8.53 1,6943 1.6931
3. Divide by smallest
value (0.6931) 3.3883/1.6931 8.53/1.6931 1.6943/1.6931 1.6931/1.6931
= 2.001 5.038 1.0007 1
4. Whole number ratio 2 5 1 1
The empirical formula = C2H5NO