i just cant understand the question
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Sr will always have 38 protons because that is its atomic number. Normally Sr has 38 protons and 49 neutrons yielding an atomic mass of 87. unless you are dealing with an isotope of Strontium in which 3 additional neutrons would give you the 53 neutrons in your answer, (38p, 52n).
Answer:
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Explanation:
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⇒The composition , decomposition or displacement of molecules of matter during chemical change is called chemical reaction.
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Various conditions bring about these changes. The chemical reactions are represented by chemicalequation. The compounds or elements that take part in chemical reaction are called reactant. They are written at the left side of an arrow that represent a change while the compound or elements that formed after the chemical change are called product. They are written at the right side of the arrow.
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When nitrogen reacts with hydrogen to form ammonia :
Nitrogen + Hydrogen ⇒ Ammonia
N₂ + 3H₂ ⇒ 2NH₃
<u>Presentation </u><u>of </u><u>a </u><u>chemical </u><u>reaction </u><u>in </u><u>the </u><u>form </u><u>of </u><u>equation </u><u>is </u><u>called </u><u>chemical </u><u>equation </u>. <u>Chemical equation may be word equations or formula equations.</u>
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Answer:
A
Explanation:
Because the amount of electrons in the outer shell can be a maximum of 8
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Answer:
A = 0.75 ×10² KJ.
B = 3.9 ×10³ dg
C = 0.22 × 10² μl.
Explanation:
A = 7.5 ×10⁴ j to kilo joules
7.5 ×10⁴ / 1000 = 0.75 ×10² KJ.
Joule is the smaller unit while kilo joule is the larger unit. One kilo joule equals to the thousand joule that's why we will divide the given value by 1000 in order to convert into KJ.
B = 3.9 ×10⁵ mg to decigrams.
3.9 ×10⁵ / 100 = 3.9 ×10³ dg
Decigram is larger unit while milligram is smaller unit. One decigram is equal to the 100 milligram. In order to convert the given value into decigram we have to divide the value by 100.
C = 2.21 ×10⁻⁴ dL to micorliters
2.21 ×10⁻⁴ ×10⁵ = 0.22 × 10² μl.
Deciliter is bigger unit then micro liter . One deciliter equals to the 100000 micro liters. In order to convert the dL into micro liter we have to multiply the given value with 100000.
