Answer:
You can identify an unknown substance by measuring its density and comparing your result to a list of known densities. Density = mass/volume. . You divide the mass by the volume and compare the density to a list of known densities.
I believe both C) and D) are correct, because both have enough electrons to show that the element has enough protons to be a transition metal, and both elements seem to have an electron configuration that exists in the ground state. We may need more information.
Answer:
Explanation:
The question is asking to write the <em>isotopic symbol </em>of the form 
for the <em>sodium isotope with 13 neutrons</em>.
In general, the isotopic symbol in the given form shows:
- The element's chemical symbol: X
- A: mass number of the isotope, written as a superscript to the left of the element's simbol, and
A = number of protons + number of neutrons
- Z: atomic number of the isotope, written as a subscript to the left of the elements's symbol,
Z = number of protons
The atomic symbol of sodium is Na.
The atomic number, or number of protons, is the same for every isotope of the element, and you can find it in any periodic table. Tha atomic number of sodium is 11. Thus:
The mass number is the number of protons plus neutrons, hence:
Now you can write the isotope symbol for the sodium isotope with 13 neutrons:
Answers and explanation:
To answer these questions you use a periodic table.
A is In because it has 49 protons and In is element number 49.
B is 27 because Co is element number 27.
C is 73 because Ta is element number 73.
D is 49 because the number of electrons in an atoms is always equal to the number of protons.
E is 56 because the atomic number of Ba is 56.
F is 54 because 56 - 54 = 2. The charge is equal to the number of protons minus the number of electrons.
G is 66. The number of neutrons is equal to the atomic mass minus the number of protons. 115 - 49 = 66.
H is 108 because 181 - 73 = 108.
I is 32. The atomic mass of an element is equal to the amount of protons plus the amount of neutrons. So 16 + 16 = 32.
