Answer:
Electron dot diagram is attached below
Explanation:
Sodium is alkali metal and present in group one. It has one valence electron. All alkali metal form salt when react with halogens.
Sodium loses its one electron to get stable. While all halogens have seven valence electrons they need only one electron to get stable electronic configuration.
When alkali metals such as sodium react with halogen fluorine it loses its one valence electron which is accepted by fluorine and ionic bond is formed. The compound formed is called sodium fluoride.
Na + F → NaF
In cross and dot diagram electrons of one atom are shown as dots while other atom shown as cross to distinguish.
Electron dot diagram is attached below.
Answer:
B. 4 ham slices
Explanation:
A chemical reaction involves one or more substances known as reactants combining chemically to give one or more substances known as products.
Reactants in chemical reactions combine in definite mole or mass ratios to give products. Therefore, when one substance is present in excess of what is required to combine with another to form products, that substance is known as the excess reagent. The other substance which is present in a smaller amount and which when used up, the reaction stops is known as the limiting reagent.
From the illustration of the sandwiches in the question, the recipe for one sandwich represents the chemical equation of a reaction. The equation form is given below:
2 cheese slices + 1 ham slice + 2 bread slices ---> 1 sandwich
The ratio of the reactant is 2 : 1 : 2
From the available ingredients, 12 cheese slices, 10 ham slices, 12 bread slices.
12 cheese slices will require 6 ham slices and 12 bread slices to produce 6 sandwiches.
However, since there are 10 ham slices, 4 ham slices will be left over unused. This is the excess or leftover reactant.
Pb2+(aq) + CO3 2-(aq) ==> PbCO3(s)
Ammonia is a (Lewis) base. Ammonium hydroxide (not ammonia) is a base. Ammonium hydroxide: NH4OH (ammonia gas dissolved in water) Ammonia: NH3
