The SI base unit for length is meter.
In order to make smaller measurements, you can use the centi-, milli-, micro-, etc. prefixes.
When you want to reference larger measurements, you can use the kilo-, mega-, giga- and prefixes such as those.
Answer:
New experimental methods
Technological inventions
Explanation:
A scientific theory is usually not based on speculation. Scientific theories must have a solid empirical basis.
However, experimental methods are limited to the caliber of equipments available at the time in which a theory is formulated. With advancing years, more technological sophistication leads to the invention of new instruments and ultimately, the development of new experimental methods.
These innovations are likely to alter existing scientific theories as new evidences emerge, hence the answer.
X-rays are found in the given region.
Answer: Option B
<u>Explanation:</u>
The wavelengths of different waves are studied carefully, and their range is determined according to the frequency they exhibited. And based upon the studies, the electromagnetic waves are classified into eight different categories such as gamma, X-, UV, visible, near IR, middle IR, far IR, micro and radio waves.
And each category has different wavelengths and the given radiation falls under X-rays. The wavelength range of X-rays varies from 1 nm to 1 pm. Here, “nm” stands for nano meter and “pm” stands for “pico meter”.
Answer:
141g of CCl₄
Explanation:
First, we have to write the balanced equation.
CCl₄(g) + 2 HF(g) ⇄ CF₂Cl₂(g) + 2 HCl(g)
We can calculate how many moles of CF₂Cl₂ using the ideal gas equation.
V = 14.9 dm³ = 14.9 L
T = 21°C + 273.15 = 294.15 K
P = 1.48 atm
R = 0.08206 atm.L/mol.K
We can use proportions to find the mass of CCl₄ required to obtain 0.914 moles of CF₂Cl₂. According to the balanced equation, 1 mol of CF₂Cl₂ is produced when 1 mol of CCl₄ reacts. And the molar mass of CCl₄ is 154 g/mol.
