Answer:
d
Explanation:
Valence electrons are in the outermost shell. They form chemical bonds with other elements, not any other electrons. Hope this helps!
Fossil fuels are considered to be:
a.
irreplaceable resources
c.
renewable resources
b.
nonrenewable resources
d.
hazardous wastes
Please select the best answer from the choices provided
A
B
C
D
How many moles are in 2.11 x 1014 molecules of LiBr?
Answer: There are [tex]12.71 \times 10^{-9}[/tex] moles present in [tex]2.11 \times 10^{14}[/tex] molecules of LiBr.
Explanation:
According to the mole concept, there are [tex]6.022 \times 10^{23}[/tex] molecules present in 1 mole of a substance.
Hence, moles in [tex]2.11 \times 10^{14}[/tex] molecules of LiBr are calculated as follows.
[tex]Moles = \frac{2.11 \times 10^{14}}{6.022 \times 10^{23}}\\= 12.71 \times 10^{-9}[/tex]
Thus, we can conclude that there are [tex]12.71 \times 10^{-9}[/tex] moles present in [tex]2.11 \times 10^{14}[/tex] molecules of LiBr.
Which of the following represents an element ? H2O H2 NaCl CaCO3
Answer:
H₂
Explanation:
H₂ is hydrogen in its elemental form.
H₂O, NaCl, and CaCO₃ are all examples of elements added together to create compounds.
Suppose that you want to make 12 g of lithium oxide.
What are the minimum masses of lithium and oxygen you will need?
A. Li= 5.6 g O2= 6.4 g
B. Li 6.5 g O2= 4.6 g
C. Li= 0.6 g O2 46.4 g
D. Li= 15.6 g O2 6.4 g
Answer:
A. Li= 5.6 g O2= 6.4 g
Explanation:
Lithium oxide, Li2O, is an oxide that contains 2 moles of Li and 1 mole of O per mole of oxide. To solve this question we must find the mass of each atom in the molecule as follows:
2Li = 2*6.941g/mol = 13.882g/mol
O = 1*16g/mol = 16g/mol
Molar mass Li2O:
16+13.882 = 29.882g/mol
The mass of lithium is:
12g * (13.882g/mol / 29.882g/mol) = 5.6g Li
And the mass of oxygen:
12g * (16g/mol / 29.882g/mol) = 6.4g O
Right answer is:
A. Li= 5.6 g O2= 6.4 gThe ideal gas law equation is: PV = nRT
Use the ideal gas law to calculate the moles of gas in a container that has a pressure
of 700kpa, volume of 2L and a temperature of 450K.
Answer:
The answer is the first option 0.37 moles
Explanation:
the ideal gas law is PV = nRT, so in the terms of n,
n = PV/RT (divide both sides by RT to let n stand alone)
given: P = 700 kpa, V = 2L, T = 450 K , R = 8.31
n = (700 * 2) / (8.31 * 450)
= 1400/3739.5
= 0.34
How or why does lead affect bones and teeth?
Answer:
Lead can harm production of blood cells and the absorption of calcium needed for strong bones and teeth, muscle movements, and the work of nerves and blood vessels. High lead levels can cause brain and kidney damage.
thanks
Once lead enters the body, it is distributed to organs such as the brain, kidneys, liver and bones. The body stores lead in the teeth and bones where it accumulates over time. Lead stored in bone may be remobilized into the blood during pregnancy, thus exposing the fetus.
What can a nation do to improve the exchange rate of its currency?
A.
try to improve its balance of trade
B.
try to decrease its trade surplus
C.
try to lower its gross domestic product (GDP)
D.
try to export less while importing more
Answer:
A
Explanation:
balance the trades and improving them
Answer:
A:try to improve it's balance of trade
Explanation:
Which has more molecules in it 10g H, 0 or 10g NaCl*
A)010g of H0
B)10g of NaCl
C)They have the same number of molecules
D)Cannot be determined
Answer:
10 grams of hydrogen
Explanation:
Which of these takes place when a chemical change occurs? option 1: Bonds connecting atoms in products and reactants form. option 2: Bonds connecting atoms in products and reactants break. option 3: Bonds connecting atoms in reactants break, and bonds connecting atoms in products form. option 4: Bonds connecting atoms in reactants form, and bonds connecting atoms in products break.
Answer: Out of the given options bonds connecting atoms in reactants break, and bonds connecting atoms in products form are the changes which takes place when a chemical change occurs.
Explanation:
A change that leads to the change in chemical composition of a substance is called a chemical change.
For example, [tex]2NH_{3} \rightarrow N_{2} + 3H_{2}[/tex]
Here, bond between the reactant atoms nitrogen and hydrogen is broken down.
On the other hand, bond connecting the products that is [tex]N_{2}[/tex] and [tex]H_{2}[/tex] is formed.
Thus,, we can conclude that out of the given options bonds connecting atoms in reactants break, and bonds connecting atoms in products form are the changes which takes place when a chemical change occurs.
Fill in the coefficients that will balance the following reaction:
A gas fills up a container that has 2.5L has a pressure of 3.5 atm. If the gas gets transferred to a container that holds 4L, what would the new pressure be?
HELP ;-;
Vanillin, C8H8O3, the principal component of vanilla beans, is very similar to glucose, C6H12O6 a type of sugar. Brittany Spears has a life threatening allergy to vanillin. After one of her concerts she was found dead in her dressing room. A glass lined with a white powder was found smashed on the floor next to her. Police think the glass was lined with vanillin suggesting she was murdered. A 2.54 g sample of this powder underwent carbon-hydrogen analysis. It’s combustion was found to produce 5.875 g of CO2 (g) and 2.41 g of H2O(g) . Find the empirical formula of this compound and determine if Brittany may have been poisoned?
b) Is this evidence enough to conclude for certain that the identity of the powder on the glass is indeed vanillin? Why or why not?
Answer:
The empirical formula is: CH2
Th powder is not vainillin
Explanation:
We can find empirical formula of a compound CₐHₓOₙ knowing that moles CO2 = Moles C, 2 Moles H2O = Moles H and that we can find the mass of oxygen by the difference of masses of the atoms:
Moles C = Moles CO2 -Molar mass: 44.01g/mol-
5.875g * (1mol/44.01g) = 0.1335 moles C * (12.01g/mol) = 1.60gC
Moles H2O and moles H -Molar mass: 18.01g/mol-
2.41g H2O * (1mol / 18.01g) = 0.1339 moles H2O * (2mol H / 1mol H2O) =
0.2676 moles H * (1g/mol) = 0.27g H
The empirical formula of this compound is the ratio of C:H:
0.2676 moles H / 0.1335 moles C = 2
The empirical formula is:
CH2
In vainillin, the moles of Carbon = Moles of Hydrogen. the experiment shows the moles of hydrogen are twice the moles of carbon. Thus, the powder is not vainillin
Explain why the buffering action of these chemical reactions is limited by the present day rate of change for atmospheric CO2 concentration
Answer:
Due to increase in carbondioxide gas.
Explanation:
The buffering action of these chemical reactions is limited by the present day rate of change for atmospheric carbondioxide concentration because the the rate of atmospheric carbondioxide rises as compared to ancient atmospheric carbondioxide gas. Due to increase of human activities, the concentration of carbondioxide gas increases in the atmosphere which limits the buffering action of these chemical reactions so we can say that carbondioxide gas is responsible for its limited action.
Magnesium is added to dilute hydrochloric acid. This makes bubbles of hydrogen and a colorless solution of magnesium chloride. Write down the name of one of the products of this reaction.
Answer:
The products are already in the question Hydrogen gas and Magnesium Chloride
Explanation:
2Mg +2HCl₂ = 2MgCl₂ + H₂ balanced equation if you need it
When any metal react with acid then salt and hydrogen gas is formed. Hydrogen gas and Magnesium Chloride are formed when Magnesium is added to dilute hydrochloric acid.
What is chemical reaction?Chemical reaction is a process in which two or more than two molecules collide in right orientation and energy to form a new chemical compound. The mass of the overall reaction should be conserved. There are so many types of chemical reaction reaction like combination reaction, double displacement reaction.
The products are Hydrogen gas and Magnesium Chloride. The balanced equation can be written as
Mg +2HCl[tex]\rightarrow[/tex] MgCl₂ + H₂
This makes bubbles of hydrogen and a colorless solution of magnesium chloride.
Therefore Hydrogen gas and Magnesium Chloride are formed when Magnesium is added to dilute hydrochloric acid.
Learn more about the chemical reactions, here:
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Which type of bond is found in an alkane?
O A. Double only
B. Single and double
O C. Single only
O D. Single and triple
Considering the definition of alkanes, single bonds are found in an alkane.
Definition of AlkanesAlkanes are a class of hydrocarbons (compounds containing only carbon and hydrogen) that are made up of a variable number of carbon atoms joined together by single bonds. In turn, each carbon atom bonds to hydrogen atoms, which may eventually be replaced by other atoms or functional groups.
In other words, alkanes are open or closed chain molecules that are linked by simple bonds.
Alkanes are saturated hydrocarbons because the bonds between carbon atoms are simple and stable. And as mentioned, the hydrogen atoms bonded to each carbon atom can be replaced by other atoms, such as halogens (fluorine, bromine, chlorine) or various groups or “radicals”. In the latter case, the structure becomes more complex giving rise to branched alkanes.
SummaryIn summary, single bonds are found in an alkane.
Learn more about alkanes:
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Answer: C) single only
Explanation:
just got it right
Witch part of an atom is mostly empty space?
Why increasing the temperature of a gas would increase the volume of its container in gas law?
When the amount of gas in a container is increased, the volume increases. Lussac's law states that the pressure of a given amount of gas held at constant volume is directly proportional to the Kelvin temperature.
How would the balloons interaction with each other change if the balloons were moved further apart? Explain.
Explanation:
It is known that like charges repel each other and unlike charges attract each other.
As the balloons are facing each other with like charges so they will repel each other. Hence, they will move apart.
But when balloons were moved further apart then interaction between them will decrease and then there will be no force of repulsion or force of attraction.
The photograph below shows the East African Rift Valley in Africa. Which tectonic movement
of Earth’s crust is most likely responsible for this feature?
Answer:
divergence of continental crust
Explanation:
