Answer:
it a
Explanation:
You have to decide the grams you have or the grams you get once converted to moles by the atomic mass of the electron you find on the periodic table to get your amount of atoms…
For example…
65.3 grams of oxygen, you look at your periodic table to find the mass and you see it’s rounded to 16. So, you divide the 65.3 by 16, to get your atoms.
65.3/16 =4 atoms.
Answer: The correct answer is -C) Prevent the embryo from drying out.
The amniotic egg of birds and reptiles is surrounded by an outer, tough, and protective shell, which protects the egg from any damage, predators, pathogens, and drying out.
The tough shell and extra embryonic membranes create a safe environment where an embryo can develop into a whole organism (with different organs like eyes ,ears, brain, kidney, heart).
Thus, option C) is the right answer.
Chemical change, because the atoms are being rearranged and we get a new substance.
Answer:
Electronegativity varies in a predictable way across the periodic table. Electronegativity increases from bottom to top in groups, and increases from left to right across periods. Thus, fluorine is the most electronegative element, while francium is one of the least electronegative.Explanation:
Answer: potassium and rubidium
Explanation:
1) The group 1 of the periodic table contain six elements namely Lithium(Li), Sodium(Na),Potassium(K),Rubidium(Rb),Cesium(Cs) and Francium(Fr). These metals are called alkali metals because they form alkalies( i.e. strong bases capable of neutralizing acids) when they react with water.
2) The heavier alkali metals (K, Rb, and Cs) react so vigorously that they invariably explode.
3) This trend, which is not consistent with the relative magnitudes of the reduction potentials of the elements, serves as another example of the complex interplay of different forces and phenomena—in this case, kinetics and thermodynamics.