Answer: True
Explanation:
Atomic number is defined as the number of protons or the number of electrons that are present in an electrically neutral atom.
Atomic number = Number of protons = number of electrons = 2
Electronic configuration represents the total number of electrons that a neutral element contains. We add all the superscripts to know the number of electrons in an atom.
The electronic configuration will be 
As its duplet is already complete and it has noble gas configuration , it is stable with 2 valence electrons.
Answer:
In my opinion I think the answer is C you don't have to choose C
The train travells at he speed of 225 km/2.5h
now
225km=225000m
2.5 hr=150min=9000s
=>avg sp of train is=225000/9000s=25m/s
1.)Baking powder NaHCO3; sodium bicarbonate Used for baking for cooking, releases CO2 in reaction with other ingredients.
2.)Detergent Sodium sulphate, sodium hydroxide and phosphatecompounds Used for washing clothes.
3.)Toothpaste Calciuym carbonate, sodium flouride Used for cleaning teeth.
4.)Salt NaCl; Sodium Chloride Used in seasoning for cooking; also used as preservative.
5.)Vinegar C2H4O2
acetic acid, ethanoic acid
Used as preservative and for seasoning foods. Utilized for various household cleaning uses.