An atom's lewis dot structure has two dots. which of the following elements could it be, and why? calcium, because it is an alkaline earth metal with two inner shell electrons. carbon, because it has two electrons in its outermost p sublevel. lithium, because it is a group 1 element with two bonding electrons. magnesium, because it is a group 2 element with two valence electrons.

D. Magnesium, because it is a group 2 element with two valence electrons.

An atom's Lewis dot structure has two dots. Which of the following elements could it be, and why?

A. Calcium, because it is an alkaline earth metal with two inner shell electrons.

B. Carbon, because it has two electrons in its outermost p sublevel.

C. Lithium, because it is a group 1 element with two bonding electrons.

D. Magnesium, because it is a group 2 element with two valence electrons.

Explanation:

If you were to look at the periodic table magnesium would be in group 2. Since magnesium is in group 2 therefore it will have two valence electrons. Calcium is another possible answer because it is also in group two, but for this quiz it is incorrect. Lithium is incorrect because it is in group 1 and therefore it would only have 1 valence electron. Carbon is also incorrect because it is in group 14 so it would have 4 valence electrons. Hope this helps and makes sense.

Good Luck!!

Answer : The correct option is, Magnesium because it is a group 2 element with two valence electrons.

Explanation :

Atomic number = 20

Electronic configuration of Ca =

Number of valence electrons in Ca = 2

The number of inner shell electrons in Ca = 18

This option is wrong because lewis-dot structure shows only valence electrons not inner shell electrons.

Atomic number = 6

Electronic configuration of C =

Number of valence electrons in C = 4

This option is wrong because only outermost p-sublevel electrons are not showing in lewis-dot structure.

Atomic number = 3

Electronic configuration of Li =

Number of valence electrons in Li = 1

This option is wrong because it has only 1 electron in outermost shell.

Atomic number = 12

Electronic configuration of Ma =

Number of valence electrons in Ma = 2

This option is correct.

Lewis-dot structure : It is defined as the structure in which valence electrons of the atom is shown as dots.

The lewis-dot structure of these elements are shown below.

pre-sliced bread is a relatively recent development in baking technology. previous to that, it was always sold in a bakery in daily-made contiguous loaves with no wrapping, and was moderately perishable, usually being used with a day or two (which is why every bakery had a discounted “day-old” bread table.) therefore, pre-sliced bread would grow stale quickly. the hard crust provided a protective layer, and once the exposed dry slice left from the previous cut was removed, the interior was still soft.

what keeps bread soft is the moisture retained in the crumb (the light spongy part that’s not crust). the reason the crust develops is the surface of the dough gets exposed to hot dry air during baking which browns the outer layer and seals it, preventing all the moisture from escaping the dough. longer exposure to air will also eventually cause your bread to lose flavor and become stale.

people were used to cutting slices as they needed them and storing bread in a specially-made wooden or metal breadbox or pail with a lid to preserve it longer, but the first automatically sliced commercial loaves were produced on july 6, 1928, in chillicothe, missouri, using a machine invented by otto rohwedder, an iowa-born, missouri-based jeweler.[1] pre-sliced bread would indeed dry out, were it not for another 20th century technology: the plastic bag. bread could now be pre-sliced, and if the enclosing bag remains sealed as much as possible, the bread will remain soft and fresh for longer than if sitting unwrapped on a shelf or enclosed in a bread box that is not air-tight. sealed packaging meant bread could also be sold on store shelves and eliminate frequent trips to a bakery.

sealing bread in a plastic bag had another effect: the moisture in the loaf will re-distribute into the crust and soften it, which is sometimes more pleasing in a sandwich - especially for children whose teeth might not yet be strong enough to tear through a hard crust. a homemade loaf of bread can be sealed in a bag overnight and the crust will become soft like store-bought sandwich bread.

these were novel changes in how bread was produced and sold, which led to the coining of the phrase “the greatest thing since sliced bread.”