Answer:
11
Explanation:
Data obtained from the question include:
Mass number = 23
Neutron = 12
Atomic number =.?
Next, we shall determine the number of protons present in the element.
This can be achieved by doing the following:
Mass number = Proton + Neutron
Mass number = 23
Neutron = 12
Proton =...?
Mass number = Proton + Neutron
23 = Proton + 12
Collect like terms
Proton = 23 – 12
Proton = 11
The atomic number of an element is equal to the proton number.
Atomic number = proton number
Proton number = 11
Atomic number = proton = 11
Therefore, the atomic number is 11.
Answer:
As you go down group 1, the number of electron shells increases – lithium has two, sodium has three, and so forth. The attraction from the positive nucleus to the negative electron is less. This makes it easier to remove the electron and makes the atom more reactive.
Answer:
3.918 mol Al
Explanation:
To convert between moles and grams, you have to use the molar mass of the substance. The molar mass of aluminum is 26.98 g/mol. You use this as the unit converter.
Round the number to the lowest number of significant figures; 3.918 mol Al
Answer:
B). Precision.
Explanation:
During the course of measurements, two important factors are been seen to play key part which are accuracy and also precision. Precision here can reflect to the closeness of an answer towards the main value even though accuracy can show that too. Also it can show series of values been reproduced in the measurement flow; though in some cases can be a bit far from the actual value. Also its values are swen to be different because of repeatition and alsio in some cases, observational errors too.
It would actually remain the same nothing will change.
