The traditional calcium atom has twenty protons and twenty electrons making it neutral.
The calcium in the pic is a calcium ion so the number of protons and electrons are not equivalent.
Since it's 2+ that means the ion is positively charged and for that to happen electrons are away.
So 20-2=18
There are 18 electrons
Molality is defined as 1 mole of a solute in 1 kg of solvent.
Molality=

Number of moles of solute, n=

Given mass of the nitrobenzene=0.2 g
Molar mass of the substance= 123.06 g mol⁻¹
Number of moles of nitrobenzene,

Number of moles of nitrobenzene, n= 0.0016 mol
Mass of 10.9 g of naphthalene in kg=0.0109

Molality= 0.146 m
Answer:
Data Scientist
Explanation:
Data Scientist (different from a statistician) is a type of researcher that uses computer softwares to analyse and make sense of raw digital data.
Data Scientists usually combine knowledge of computer science, statistics and mathematics while using various softwares to extract information and meaningful, key insights (whether structured or unstructured) from data.
There are two popular types of data scientists: Operational Data Scientists (experts in software implementations and day to day running of the data science wing of a firm) and Exploratory Data Scientists (The real digital data miners, the researchers).
With the way the world is set up now that data is everything, data scientists are a must for every firm as the raw data every firm collects is processed by data scientists.
144 years, its simple math?
Answer:
Methane is present in solid, liquid and gaseous form.
Explanation:
Methane hydrate is present in solid state when the hydrogen-bonded water and methane gas come into contact at high pressures and low temperatures in the deep oceans while on the other hand, methane which is present inside the earth surface in gaseous form due to non-availability of water that can combine with methane. Methane is also found in liquid form when it is cool with high pressure and low temperature.