2.1 kg of sodium bicarbonate is equal to the 2.1 x 10¹² ng of sample. Option D is correct.
Mass is the quantity of the substance in the body or object. The SI unit of mass is Kilogram.
There are other units of measure,
- Milligram: 1 g is equal to the

- Micro-gram: 1 g is equal to

- Nano-gram: 1 g is is equal to
First convert kg to gram,
Since, 1 Kg = 1000 g
2.1 kg = grams of sample
So,
Do the cross multiplication,

Now, convert 2100 g to nano-grams
Since, 1 g = 1 x 10⁹ ng
2100 g = ng of sample
So,
Do the cross multiplication,

Therefore, 2.1 kg of sodium bicarbonate is equal to the 2.1 x 10¹² ng of sample.
To know more about Mass units,
brainly.com/question/489186
Answer:
A physical change is a change to the physical—as opposed to chemical—properties of a substance. They are usually reversible. The physical properties of a substance include such characteristics as shape (volume and size), color, texture, flexibility, density, and mass.
Explanation:
PLS MARK AS THE BRAINLIEST
Answer:
A(n) <u>living wage</u> is the idea that people should be able to purchase the essentials of life by working a forty-hour workweek. Many local municipalities have as a result set higher minimum wages than the federally mandated minimum wage to accomplish this goal.
Explanation:
Living wage is the idea given to reduce poverty specially in cities with higher costs. It's based on the fact that one who works forty hours per week, he or she should be able to afford the basic needs of life that includes the water, food and shelter. Research has shown that the implementation of this concept has played the role in reducing poverty and enhancing the quality of life of workers. Countries like New-Zealand and united kingdom has supported this concept.
Answer:
One gram of pure gold would contain lots of gold atoms- A.
Hydrogen is written as H2 and oxygen is written as O2
When they bond it is a covalent bond.
Hydrogen has 1 negative electron , which would attract one from oxygen, so its outer shell would have 2 electrons.
Oxygen outer shell holds 8 electrons.
The answer is
2 and 8