The unknown substance : Lead
<h3>Further explanation</h3>
Given
Density of element
mass of unknown substance = 40 g
volume = 3.5 cm³
Required
The density of unknown substance
Solution
Density is the ratio of mass per unit volume
The unit of density can be expressed in g/cm³ or kg/m³
Density formula:

Input the value to find the density of an unknown substance :
ρ = 40 g : 3.5 cm³
ρ = 11.43 g/cm³
If we look at the table, the substance which has a density of 11.43 is Lead
The products enable our nations efforts to improve energy efficiency . From insulation to coolants to packaging , the product of chemistry help save energy day . But chemistry also is the source of many innovative technologies that drive cleaner energy options , create green jobs and propel u.s. economic growth.
Explanation:
Different atoms absorb and emit specific wavelengths of electromagnetic radiation and nothing in between. These absorption and emission spectra are actually used to identify atoms of elements in a substance. This phenomenon is explained by Bohr's theory of quantized energy levels in an atom – called orbital levels. When an electron 'jumps' from a lower to higher orbital level, it absorbs a specific wavelength of electromagnetic radiation specific to the ‘jump’. Vice versa, when an electron 'jumps' to a lower orbital level is emits an equivalent and specific wavelength of electromagnetic radiation.
Learn More:
For more on emission spectra check out;
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then the electrons and protons would have a even amount of negetive electric charges
"Polysaccharide carbohydrate" comprises an S. pneumoniae capsule.
<u>Option:</u> C
<u>Explanation:</u>
The lengthy sequences of carbohydrate molecules, primarily polymeric carbohydrates constructed of units of monosaccharides linked together through glycosidic connections, understood as Polysaccharides. This carbohydrate can respond to water by catalyzing amylase enzymes, which generate component sugars.
A major human pathogen is Streptococcus pneumoniae or pneumococcus. The virulence is primarily due to its polysaccharide envelope, which protects it from the recipient immune response, and this has led to comprehensive study of the shell.