Which elements did the Curies discover?

An ionic bond occurs between what particles

kakasveta [241]

<span>The correct answer is that an ionic bond forms between charged particles. To form this bond, the particles transfer valence electrons (those in the outermost orbit). Specifically, in ionic bonding, the metal atom loses its electrons (thus becoming positive) and the nonmetal atom gains electrons (thus becoming negative).</span>

4 0

3 years ago

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A sample of rubidium contains two different isotopes. 72.15% of the sample

Leona [35]

Answer:

Average atomic mass = 85.557 amu.

Explanation:

Given data:

Percent abundance of Rb-85 = 72.15%

Percent abundance of Rb-87 = 27.85%

Average atomic mass = ?

Solution:

Average atomic mass = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass) / 100

Average atomic mass = (72.15×85)+(27.85×87) /100

Average atomic mass = 6132.75 + 2422.95 / 100

Average atomic mass = 8555.7 / 100

Average atomic mass = 85.557 amu.

4 0

2 years ago

Electrophilic addition of hbr to 3-methyl-2-hexene creates an asymmetric center at c-2. what is the product of this reaction?

AleksandrR [38]

This reaction would give rise to two products.

2-bromo-3-methylhexane, and
3-bromo-3-methylhexane.

However, 2-bromo-3-methylhexane would be more common than 3-bromo-3-methylhexane among the products.

The hydrogen atom in a hydrogen bromide molecule carries a partial positive charge. It is attracted to the double bond region with a high electron density. The hydrogen-bromine bond breaks when HBr gets too close to a double bond to produces a proton $\text{H}^{+}$ and a bromide ion $\text{Br}^{-}$ .

The proton would attack the double bond to produce a carbocation. It could attach itself to either the second or the third carbon atom.

$\phantom{\text{H}_3\text{C}-\text{CH}-\;}+\\\text{H}_3\text{C}-\text{CH}-\text{CH}-\text{CH}_2-\text{CH}_2-\text{CH}_3\\\phantom{\text{H}_3\text{C}-\;\;}|\phantom{\text{CH}-}\;}|\\\phantom{\text{H}_3\text{C}-\;} \text{H}\phantom{\text{CH}}\;\;}\text{CH}_3$
$\phantom{\text{H}_3\text{C}-\text{CH}-}\;\;\text{H}\\\phantom{\text{H}_3\text{C}-\;}+\phantom{\text{H}-\;}|\\\text{H}_3\text{C}-\text{CH}-\text{CH}-\text{CH}_2-\text{CH}_2-\text{CH}_3\\\phantom{\text{H}_3\text{C}-\;\;\;}\phantom{\text{CH}-}\;}|\\\phantom{\text{H}_3\text{C}-\;} \phantom{\text{H}}\phantom{\text{CH}}\;\;}\text{CH}_3$

Carbocations are unstable and might decompose over time. The first carbocation is more stable than the second for having three alkyl groups- i.e., straight carbon chains- attached to the center of the positive charge. Alkyl groups have stabilizing positive induction effect on positively-charged carbon. The second carbocation has only two, and is therefore not as stable. The first carbocation thus has the greatest chance to react with a bromide ion to produce a stable halocarbon.

Bromide ions are negatively charged. They attach themselves to carbocations at the center of positive charge. Adding a bromide ion to the first carbocation would produce 3-bromo-3-methylhexane whereas adding to the second produces 2-bromo-3-methylhexane.

The <em>most likely</em> product of this reaction is therefore 3-bromo-3-methylhexane.

6 0

3 years ago

How does most ocean water return to the ocean in the water cycle?

abruzzese [7]

The sun, which drives the water cycle, heats water in the oceans. Some of it evaporates as vapor into the air. ... Most precipitation falls back into the oceans or onto land, where, due to gravity, the precipitation flows over the ground as surface runoff.

7 0

3 years ago

Some chemical reactions releases energy other store energy what important chemical reaction storage energy?

olganol [36]

Answer:

A chemical reaction that stores energy is called an endothermic reaction. More energy might be released as products form than the energy needed to break the reactants apart. This chemical reaction will release energy. In other words, it will be an exothermic reaction.

Explanation:

6 0

2 years ago

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