The amount left after 20 years = 154.15 mg
<h3>Further explanation
</h3>
The atomic nucleus can experience decay into 2 particles or more due to the instability of its atomic nucleus.
Usually radioactive elements have an unstable atomic nucleus.
The main particles are emitted by radioactive elements so that they generally decay are alpha (α), beta (β) and gamma (γ) particles
The decay formula for isotope :

Then for t=20 years, the amount left :

Explanation:
Non-metals are the species that are electron deficient and they are able to accept one or more electrons from a donor atom in order to complete their octet.
For example, carbon (C), nitrogen (N), chlorine, (Cl), phosphorus (P) etc are all non-metals.
Metals are the species that contain more number of electrons in their valence shell and in order to attain stability they easily lose an electron.
For example, sodium (Na), lithium (Li), Beryllium (Be), Magnesium (Mg) etc are all metals.
Metalloids are the species that show properties of both metals and non-metals.
For example, Boron (B), Antimony (Sb), Silicon (Si) and Germanium (Ge) etc are metalloids.
Answer: 1. Block
2. True ( I'm unsure. He arranged it according to mass, but he is credited for the periodic table)
3. Noble gasses
4. technetium
5. Alkaline earth metals
6. Number of protons
7. False
8. Not true: generally decreases as atomic number increases within a period
9. Argon
10. Four
11. False
12. False
Explanation:
Answer:
<u>When small organic molecules bind together, they form larger molecules called biological macromolecules.</u>Biological macromolecules are important cellular components and perform a wide array of functions necessary for the survival and growth of living organisms. The four major classes of biological macromolecules are carbohydrates, lipids, proteins, and nucleic acids.
(i hope this helps)
Answer:
Genotypes: Homozygous (GG)=50%, Heterozygous (Gg)=50%.
Phenotypes: Homozygous gray (GG)=50%, Heterozygous gray (Gg)=50% or just Gray=100%
Explanation:
Hello,
The Punnett square for this cross turns into:
![\left[\begin{array}{ccc}&G&g\\G&GG&Gg\\G&GG&Gg\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D%26G%26g%5C%5CG%26GG%26Gg%5C%5CG%26GG%26Gg%5Cend%7Barray%7D%5Cright%5D)
It means that the genotypes and phenotypes are:
Genotypes: Homozygous (GG)=50%, Heterozygous (Gg)=50%.
Phenotypes: Homozygous gray (GG)=50%, Heterozygous gray (Gg)=50% or just Gray=100%
Best regards.