Answer:
C.
Explanation:
Since the mass number is the number of protons and neutrons added together, the answer is 35. Since the questions are respectively electron quantity and mass number, the only answer choice with 35 as the second choice is C, so that is the correct answer.
Answer:
False.
Explanation:
all planets have gravity because if they didnt, the gasses and whatever makes up the planet wouldnt be pulled down to the core of the planet, and it would just be floating around in space.
When electrons in atom interaction with light or photons one of the two process takes place:
1) they can absorb photons of a characteristic wavelength (which depends on the energy difference between two interacting atomic levels) and get excited to a higher energy level
2) or they can jump to a lower energy level and emit photons of the corresponding wavelength.
The type of spectrum produced when electrons in an atom undergo transitions to various levels by absorbing or emitting photons is termed as atomic spectrum.
Answer:
A) it is converted to an SI unit of measurement
Explanation:
The SI, System International units are the fundamental units used to measure the scientific quantities.
Example of SI units are Kilogram (km) for distance, liter (l) for liquid, centimeter (cm), and meter (m) for size of the object or short distance etcetera.
SI units help to differentiate quantities from each other and without using SI unit, no one can identify the category of the quantity whether it is distance, size or volume.
Hence, the correct answer is "A) it is converted to an SI unit of measurement".
The smallest and the basic particle of a chemical element is said to be an atom. It is made up of three subatomic particles that is electrons, protons and neutrons. The neutrons and protons are present in the nucleus of an atom whereas electrons are present in the orbits around the nucleus of the atom. There are several shells in the orbital depending on the atomic number. The electrons which are present in the outermost shell are said to be valence electrons.
They can be determined by the electronic configuration of the element.
The atomic number of strontium, 
is 38. The electronic configuration of strontium, is:
From the electronic configuration it is clear that the outermost shell of strontium, is 
. So, the number of valence electrons in strontium, is 2.
Hence, there are 2 valence electrons in an atom of strontium ().
