<span>Organisms in biological ecosystems connect to one another through their need for matter as well as energy. Every organism needs molecules like proteins, carbohydrates, and fats to provide the raw building materials for their cells.</span>
Answer:
1.20 M (3 s.f.)
Explanation:
In this question, we are trying to find the concentration of KCl after dilution. Note that the number of moles of KCl does not change.
Number of moles of KCl
= 44.7 ÷74.55
= 0.59960 mol (5 s.f.)
New volume
= 500 mL
= (500 ÷1000) L
= 0.5 L
Concentration after dilution
= 0.59960 ÷0.5
= 1.1992 mol/L
= 1.20 M (3 s.f.)
* M is the symbol for Molarity, which is also equal to mol/L
<span>I would say Antimony (Sb). Similar chemical properties are usually found within the same column of the periodic table. Look at the element above and below arsenic. I chose Sb since it is also a metaloid and Phosphorus is a nonmetal.
hope that helps </span>
Answer:
Approximately 1.9 kilograms of this rock.
Explanation:
Relative atomic mass data from a modern periodic table:
To answer this question, start by finding the mass of Pb in each kilogram of this rock.
89% of the rock is . There will be 890 grams of in one kilogram of this rock.
Formula mass of :
.
How many moles of formula units in that 890 grams of ?
.
There's one mole of in each mole of . There are thus of in one kilogram of this rock.
What will be the mass of that of ?
.
In other words, the in 1 kilogram of this rock contains of lead .
How many kilograms of the rock will contain enough to provide 1.5 kilogram of ?
.
Exothermic:
An Exothermic reaction is a chemical reaction that expels energy in the form of heat/light. Everything a Endothermic does not do. Pretty simple for this one
reactants → products + energy.
For future reference - Exo means release, thermic means heat.
<u>Energy is a Reactant </u>
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Endothermic:
An Endothermic reaction essentially is draining the heat energy from anything its its surroundings. Usually its just heat but can also be salt dissolving it water or ice melting. Another example would be frost on your windshield evaporating.
It is the exact opposite of an Exothermic reaction.
<u>Energy is a Product</u>