Answer:
(a) An experiment was conducted, response variable is the concentrations of the chemical
Explanation:
According to Oxford dictionary; an experiment is; "a scientific procedure undertaken to make a discovery, test a hypothesis, or demonstrate a known fact."
The aim of the entire study is to discover the concentration of a certain chemical at various depths of the river. This means that the entire procedure was undertaken for the purpose of discovery. Hence it is an experiment.
The independent variable here is the depth of the river while the response variable is the concentration of the chemical of interest at each depth.
A responding variable changes as changes are made in the independent variable. The variable that is manipulated in an experiment is the independent variable.
Which of the following is true for a cell that has DNA present inside a nucleus? (5 points)
It must be a part of the oldest known fossils.
It must be a part of a eukaryote.
It must be a part of a bacterium.
It has a nucleoid.
I REALLY NEED THIS RIGHT NOW IF YOU SEE THIS AND NOW THIS PLEAASE HELPPP
Answer:
It must be a part of a eukaryote
Explanation:
Eukaryotic cells are larger than prokaryotic cells and have a “true” nucleus, membrane-bound organelles, and rod-shaped chromosomes. The nucleus houses the cell's DNA and directs the synthesis of proteins and ribosomes.
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Samantha and Claire determined the mass and volume of a piece of metal to be 24.16 g and 3.22 mL respectively. Determine the density of the metal.
Answer:
7.5031055900621
Explanation:
D= M/V
In pure metals, the atoms are arranged in orderly _______
and _______
Answer:
Rows and columns.
Explanation:
Each atom gives up some of its electrons to create a kind of sea of these randomly moving charged particles. It's these free-flowing electrons that make metals conductive.
How would one make a 2 M solution of a compound?
O A. By dissolving 1 molar mass of the compound in 2L of water
OB. By dissolving 2 moles of the compound in 1 L of water
Oc. By dissolving 2 g of the compound in 1 L of water
D. By dissolving 1 mole of the compound in 2 L of water
Answer:
B. By dissolving 2 moles of the compound in 1 L of water.
Answer:
b
Explanation:
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When an oxygen-19 nucleus undergoes beta decay, the nucleus formed is
that of
oxygen-18.
O nitrogen-18.
fluorine-19.
O carbon-14.
2 Aluminum oxidizes according to the following equation: 4A1 + 302 → 2Al2O,
[a] Powdered Al (0.048 myl) is placed into a container containing 0.030 mol O.. What is the limiting reactant?
[b] How many moles of the excess reoctant remaine?
Answer:
Identify the limiting reactant (limiting reagent) in a given chemical reaction.
Calculate how much product will be produced from the limiting reactant.
Calculate how much reactant(s) remains when the reaction is complete.
please help does anybody know how to calculate the molar mass of a compound?
Genesis lays an object on the table in a well-lighted room the object absorbs all visible light waves what color object does genesis see?
Answer:
The object Genesis sees is black.
Explanation:
The color an object reflects represents what the object's color is. For example, if a block reflects blue light, then only blue light is sent to our eyes, and hence we see the block as blue.
If an object absorbs all visible light waves, then, that means there's no visible light reflected, and we cannot see any color the object has. Hence, it is black in our eyes.
Hope this helped!
5. Which elements are examples of nonmetals?
a) Sodium, potassium, and calcium
b) Silicon, germanium, and astatine
c) Barium, iron, cobalt
d) Argon, sulfur, oxygen
Answer:
B
Explanation:
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How many moles of no are produced from a reaction if it’s mass is 2.05
Answer:
6.83 × 10^–2 mol NO
Explanation:
The number of moles of nitric oxide NO produced from a reaction if its mass is 2.05 is equal to 0.0683 mol.
What is a mole?A mole is represented by the symbol mol and can be defined as a scientific unit that is used to measure the amount of the substance. The substance can commonly be chemical entities but they are individually distinct.
A mole of the substance can be used to evaluate a large number of constituent particles. The amount of substance can be measured in terms of chemical entities of a substance in a sample.
The number of elementary units in 1 mole of a substance is equal to 6.023×10²³ which is called Avogadro’s constant.
Given, the mass of the Nitric oxide, NO = 2.05 g
The mass of one mole of Nitric oxide, NO = 30 g
We can calculate moles of the substance as, n = Mass/molar mass
Then, the number of moles of Nitric oxide, NO = 2.05/30 = 0.0683 mol
Therefore, the number of moles of Nitric oxide, NO is 0.0683 mol.
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When 33 g of CaO and 10 g of H2O react, how many grams of calcium hydroxide would you expect to be produced* Explain your answer.
Answer:
Calculate the number of moles of oxygen required to react exactly with 4.30 ... How many moles of NH3 can be made from 2.00 moles of Nz if you have excess Hz? ... 10. How many grams of water are made when 3.00 moles of butanol is combusted? ... If 50.0 g of calcium oxide were produced, how many grams of calcium ...
Answer:
41.44 g
Explanation:
First of all, we must put down the equation of the reaction;
[tex]CaO + H2O ----->Ca(OH)2[/tex]
Number of moles of CaO = 33g/56 g/mol = 0.59 moles
Number of moles of H20 = 10g/18 g/mol = 0.56 moles
Since the reaction is in 1:1 mole ration, H2O is the limiting reactant
Hence;
mass of Ca(OH)2 produced = 0.56 moles * 74 g/mol = 41.44 g
DESPERATE WILL GIVE BRAINLIST AND THANKS
The half-life of an element is 150 years. If a 40-gram sample was originally deposited, how much is left
after 300 years?
Question 4 options:
30 grams
20 grams
10 grams
5 grams
Answer:
20 grams
Explanation:
40g= 300
x = 150
cross multiply, 40*150/300
6000/300= 20g
How many molecules are in 252.3 g H2S?
Answer:
4.457 × 10²⁴ molecules H₂S
General Formulas and Concepts:
Chemistry - Atomic Structure
Reading a Periodic TableUsing Dimensional AnalysisAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Explanation:
Step 1: Define
252.3 g H₂S
Step 2: Identify Conversions
Avogadro's Number
Molar Mass of H - 1.01 g/mol
Molar Mass of S - 32.07 g/mol
Molar Mass of H₂S - 2(1.01) + 32.07 = 34.09 g/mol
Step 3: Convert
[tex]252.3 \ g \ H_2S(\frac{1 \ mol \ H_2S}{34.09 \ g \ H_2S} )(\frac{6.022 \cdot 10^{23} \ molecules \ H_2S}{1 \ mol \ H_2S} )[/tex] = 4.45688 × 10²⁴ molecules H₂S
Step 4: Check
We are given 4 sig figs. Follow sig fig rules and round.
4.45688 × 10²⁴ molecules H₂S ≈ 4.457 × 10²⁴ molecules H₂S
Answer:
[tex]\boxed {\boxed {\sf 4.457*10^{24} \ molecules \ H_2S}}[/tex]
Explanation:
First, find the molar mass of H₂S
Use the Periodic Table to find the mass of hydrogen and sulfur.
Hydrogen (H): 1.008 g/mol Sulfur (S): 32.07 g/molTo find the molar mass of H₂S, multiply the molar mass of the elements by the number of atoms of the element.
Hydrogen (2): (2)(1.008 g/mol) =2.016 g/molSulfur (1 atom): (1)(32.07 g/mol)= 32.07 g/molAdd.
2.016 g/mol + 32.07 g/mol =34.086 g/molNext, find the number of moles in the sample (252.3 g) Use the ratio of grams to moles.
[tex]252.3 / g * \frac{1 \ mol \ H_2S}{34.086 \ g }[/tex]
Multiply. The grams will cancel each other out.
[tex]\frac{252.3 / mol }{34.086 \ }=7.40186587 \ mol[/tex]
Finally, found the number of molecules using Avogadro's number (There are 6.022*10²³ molecules in 1 mole).
[tex]7.40186587 \ mol \ H_2S*\frac{6.022*10^{23} molecules \ H_2S}{1 \ mol \ H_2S}[/tex]
Multiply. The mole (mol) will cancel each other out.
[tex]7.40186587*{6.022*10^{23}\ molecules \ H_2S} = 4.45740363 *10^{24} \ molecules \ H_2S[/tex]
Round to the correct number of significant figures. The sample had 4 sig figs (2, 5, 2, 3), so round to 4 sig figs.
[tex]4.457*10^{24} \ molecules \ H_2S[/tex]
There are about 4.457 * 10²⁴ molecules of H₂S
PLS HELP ASAP I DONT HAVE TIME ONLY 5 MINUTES AND IM DOING OTHER THINGS HELPP
Answer:
The reactants of photosynthesis are Carbon Dioxide and water. The products are Glucose (or starch/sugar) and Oxygen. The autotroph uses light energy from the sun in order to complete this process. In the formula, the arrow is the light energy.
Explanation:
Answer:
I've inserted an image.
Explanation:
Hope this helps!
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If the half-life of an element is 150 years, how much of a 400 gram sample would remain in 750 years?
Answer:
y
Explanation:
23) Assuming STP, how many moles are in 30 L SO2?
Answer:
1.34 moles SO₂(g)
Explanation:
At STP 1 mole of any gas occupies 22.4 Liters. So, for 30 Liters ...
moles SO₂(g) = 30L/22.4L·mol⁻¹ = 1.34 moles SO₂(g)
a speed-time graph which the displayed data forms a straight line is a example of?
Answer:
constant speed or a horizontal line is an rest
Explanation:
A student has 0.75 L of a 5.0 M solution and dilutes it to make 3.5 liters. What’s the molarity of the diluted solution?
1.1 M
2.0 M
1.6 M
.93 M
The molarity of the diluted solution : 1.1 M
Further explanationDilution is the process of adding solvent to get a more dilute solution.
The moles(n) before and after dilution are the same.
Can be formulated :
[tex]\tt n_1=n_2\\\\M_1.V_1=M_2.V_2[/tex]
M₁ = Molarity of the solution before dilution
V₁ = volume of the solution before dilution
M₂ = Molarity of the solution after dilution
V₂ = Molarity volume of the solution after dilution
M₁=5
V₁=0.75
V₂=3.5
[tex]\tt M_2=\dfrac{M_1.V_1}{V_2}\\\\M_2=\dfrac{5\times 0.75}{3.5}\\\\M_2=1.07\approx 1.1[/tex]
what would be the theoretical yield of 2SO2 + O2 + 2H2O --> 2H2SO4
Answer:
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Explanation:
Put the following elements in order from largest to smallest atomic radius
Br, Fe, Ga, Ca, Cu
Answer:
Ca-197
Ga-135
Cu-128
Fe-126
Br-114
An inherited characteristic of an organism is called a ___________________.
Answer:
fitness. the ability of an organism to survive and reproduce in its environment. adaptation. the inherited characteristic that increases an organism's chance of survival.
An inherited characteristic of an organism is called a heredity.
What do you mean by heredity ?The term heredity refers to the genetic heritage passed down by our biological parents. It is the transmission of traits from one generation to another generation. These traits can be physical, such as eye colour, blood type or a disease, or behavioral.
Heredity is also called biological inheritance, is the exiting of of traits from parents to their offspring either through asexual reproduction or sexual reproduction.
Heredity is a process in which organisms develop characteristics from their parents. These characteristics are called traits. Inheritance is the transmission of information from one generation of individuals to the next.
Thus, An inherited characteristic of an organism is called a heredity.
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WILL GIVE BRAINLIEST
If 175.0g of nitrogen is reacted with 250.0g of hydrogen, what is the theoretical yield of the reaction? What is the excess reactant? What is the limiting reactant? Show your work.
Answer:
Nitrogen gas is the limiting reactant
Hydrogen gas is the excess reactant
The theoretical yield is 425 g of ammonia
Explanation:
Equation of reaction: 3H2 + N2 ---> 2NH3
From the equation of reaction, 3 moles of hydrogen gas reacts with 1 mole of nitrogen to produce 2 moles of ammonia gas.
Molar mass of hydrogen gas = 2.0 g
Molar mass of nitrogen gas = 14.0 g
Molar mass of ammonia gas = 17.0 g
Number of moles of hydrogen gas in 250 g = 250/2 = 125 moles
Number of moles of nitrogen gas in 175 g = 175/14 = 12.5 moles
Mole ratio of Hydrogen to Oxygen = 125/12.5 = 10 : 1
Therefore, nitrogen gas is the limiting reactant.
Hydrogen gas is the excess reactant
14 g of nitrogen gas produces 17 × 2 g of ammonia = 34 g of ammonia
175 g will produce (34 × 175)/14 = 425 g of ammonia
Therefore the theoretical yield is 425 g of ammonia
How are crystals made?
Explanation:
Crystals often form in nature when liquids cool and start to harden. Certain molecules in the liquid gather together as they attempt to become stable. They do this in a uniform and repeating pattern that forms the crystal. In nature, crystals can form when liquid rock, called magma, cools.
Answer: Crystals often form in nature when liquids cool and start to harden. Certain molecules in the liquid gather together as they attempt to become stable. They do this in a uniform and repeating pattern that forms the crystal. In nature, crystals can form when liquid rock, called magma, cools.
Explanation: Can i have BrainLiest
Which model is based on Bohr's quantum model?
Model A
Model B
Model C
Model D
Answer:
Model D
Explanation:
Bohr's Model has a planetary look. Where the electrons are in an orbit.
Answer:
The answer is model D
What is not found on the inside of the eye? optic nerve, cornea, tear ducts, or iris?
If 1 kg of fuel is used in the above fusion reaction (2 1H + 3 1H--> 4 2He+1 0N) , the resulting helium has a mass of 0.993 kg. In other words, 0.007 kg of mass is converted to energy. How much energy is produced by the fusion of 1 kg of hydrogen? (Hint: Use Einstein's equation, E = mc2, where E is energy in Joules, m is mass in kilograms, and c is the speed of light, 3 x 108 m/s.)
Answer:
E--> mc2
E--> 0.007 x (3x108)2
E--> 6.3 x 1014J
Explanation:
What are gases that are molecules
Answer:
there are elemental molecules, made from one type of atom (pure), example: oxygen and there are compound molecules, made from more then one type of atom, for example carbon dioxide
Why are anions negative?
Answer:
An anion has more electrons than protons, consequently giving it a net negative charge .
hope it helps!
What is formed when atoms of elements combine?
O Compounds
O Electrons
O Protons
O Neutrons
Answer:
compounds , because they're combined
Answer:
The answer is A.) Compounds
Explanation:
Compounds are when the atoms of elements combine. When combined it creates a compound.
Alec saw footage of a landslide on the news. He saw rocks falling from the side of a mountain, with some of them smashing into each other and breaking apart. Alec witnessed
A. erosion and weathering.
B. erosion and compacting.
C. weathering and compacting.
D. weathering and sedimentation.
Answer:
a
Explanation: