Answer:
true
Explanation:
cosity a letter to our mother
who is in lagos Nigeria telling
her about the
the problem you are
facing
in the school and at
home and suggest solution to
you pproblem
Please help me l don’t understand please !!!!!!
Answer: C
Explanation:
he never had evidence in the first place that was nearly enough.
Select the correct answer.
For Al, its atomic number is 13 and its mass number is 27. How many neutrons does it have?
Ο Α. .
13
ОВ.
14
26
OD
27
O E
40
Answer:
B.) 14
Explanation:
27-13=14 neutrons
What are the two types of bonding we have studied?
a. Metallic and covalent
b. Covalent and ionic
c. lonic and metallic
d. Molecular and metallic
what is the most important part of solution preparation
Answer:
id k exactly what your asking
Explanation:
The acceleration of a baseball after it is hit by a bat depends on the mass of the ball and the net force on the ball. This example best illustrates which law?
a
Newton's law of universal gravitation.
b
Newton's first law of motion.
c
Newton's third law of motion.
d
Newton's second law of motion.
How do you decrease the amount of energy storage molecules there are in an ecosystem?
a) increase sunlight
b) decrease sunlight
c) burn dead matter
d) bury dead matter
e) trap carbon dioxide
Decreasing sunlight will decrease the amount of energy storage molecules in an ecosystem.
What is Photosynthesis?This is the process in which green plants manufacture food in the presence of sunlight. Primary producers are involved in this process of providing energy to the ecosystem.
This therefore means that a decrease in sunlight means a decrease in photosynthesis and energy production.
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Two objects of equal mass have a force of gravity of 6 N between them. Imagine the mass of one is cut in half and the other stays the same, what is the force due to gravity?
Answer:
F' = 3 N
Explanation:
Given that,
Two objects of equal mass have a force of gravity of 6 N between them.
If the mass of one is cut in half and the other stays the same such that,
m₁' = m₁ and m₂' = (m₂/2)
We need to find the new force. The gravitational force between two objects is given by :
[tex]F=G\dfrac{m_1m_2}{r^2}[/tex]
We have, F = 6 N
New force,
[tex]F'=G\dfrac{m_1'm_2'}{r^2}\\\\F'=\dfrac{Gm_1\times \dfrac{m_1}{2}}{r^2}\\\\=\dfrac{1}{2}\times \dfrac{Gm_1m_2}{r^2}\\\\F'=\dfrac{F}{2}\\\\F'=\dfrac{6}{2}\\\\F'=3\ N[/tex]
So, the new force becomes 3 N.
report speech in grammar
Explanation:
I don't understand the question
Answer:
Reported speech is often called indirect speech. Reported speech is the speech in which someone says that someone told something.
For example:
1. The English teacher said that she would take our test on Monday.
2. Mr. James said that he was not feeling well due to dry weather.
Did you observe the tense of the reported speech? It is in past form. In reported speech always use past tense.
7th grade science lol help
Answer:
The process you are referrring to is erosion.
Explanation:
Weathering would be the breaking down of rock/other land debris. Its more active counterpart would be erosion, wherein the process transports the bits of rock and minerals away. Hope it helps!
Which of the following correctly shows a synthesis reaction involving potassium?
A. Br2 + 2KI → I2 + 2KBr
B. 4K + O2 → 2K2O
C. 2KClO3 → 2KCl + 3O22KClO3 → 2KCl + 3O2
D. 2K2O → 4K + O22K2O → 4K + O2
Answer:
B. 4 K + O₂ → 2 K₂O
Explanation:
Which of the following correctly shows a synthesis reaction involving potassium?
A. Br₂ + 2 KI → I₂ + 2 KBr
No, this is a single displacement reaction, in which Br displaces I from its salt.
B. 4 K + O₂ → 2 K₂O
Yes, this is a synthesis reaction, in which 2 elements combine to form a compound.
C. 2 KClO₃ → 2 KCl + 3 O₂
No, this is a decomposition reaction, in which a big substance decomposes into smaller ones.
D. 2 K₂O → 4K + O₂
No, this is a decomposition reaction, in which a big substance decomposes into smaller ones.
How are lysosomes and vacuoles the same? How are
they different?
Answer:
This is the answer they're looking for:
Lysosomes and vacuoles both deal with waste materials. Lysosomes break down waste materials, and vacuoles store waste materials in the cell temporarily before the cell get rids of them.
Explanation:
i hope you'll pick me for brainiest
Determine how many molecules are in 86L of carbon dioxide at STP?
Answer:How can you tell how much gas is in these containers?
Small gas tanks are often used to supply gases for chemistry reactions. A gas gauge will give some information about how much is in the tank, but quantitative estimates are needed so the reaction will be able to proceed to completion. Knowing how to calculate needed parameters for gases is very helpful to avoid running out too early.
Conversions Between Moles and Gas Volume
Molar volume at STP can be used to convert from moles to gas volume and from gas volume to moles. The equality of 1 mole = 22.4 L is the basis for the conversion factor.
Sample Problem One: Converting Gas Volume to Moles
Many metals react with acids to produce hydrogen gas. A certain reaction produces 86.5 L of hydrogen gas at STP. How many moles of hydrogen were produced?
Step 1: List the known quantities and plan the problem.
Known
86.5 L H2
1 mol = 22.4 L
Unknown
moles of H2
Apply a conversion factor to convert from liters to moles.
Step 2: Calculate.
Explanation:
plz, help me it's urgent
Answer:
Explanation:
A is solid, b is melting, c is freezing, d is liquid, e is evaporating, g is gas, and f is condensation.
Hello Mikaela!
Let's start from the top, letter G. Letter G should be gas. Letter F should be condensation. Letter E should be evaporation. Letter D should be liquid. Letter C should be freezing. Letter B should be melting. And letter A should be solid.
I really hope this helps!!
The tablets were crushed, and 4.9993 g of the powder was transferred to a beaker and reacted with HCl. After filtration, the filtrate was transferred to a 100-mL volumetric flask and diluted with water. 20.00 mL of this stock solution were combined with 0.2 M Na3PO4. The resulting precipitate weighed 0.3451 g after drying. Calculate the moles of BiPO4 precipitated, the moles of Bi3 in the stock solution, and the mass of BSS per tablet.
Answer:
Explanation:
From the information given:
Mass of BiPO₄ = 0.3451 g
Number of moles of BiPO₄ = [tex]0.3451 \ g \ BiPO_4 \times \dfrac{1 \ mol \ BiPO_4}{303.95 \ g \ BiPO_4}[/tex]
[tex]= 0.001135 \ mol[/tex]
The number of moles of Bi³⁺ in 20.00 mL is:[tex]= 0.001135 \ mol \ BiPO_4 \times \dfrac{1 \ mol \ of \ Bi^{3+}}{1 \ mol \ BiPO_4}[/tex]
= 0.001135 mol of Bi³⁺
The number of moles of Bi³⁺ in 100 mL stock solution
[tex]= 0.001135 \ mol \ Bi^{3+} \times \dfrac{100 \ mL}{20.0 \ mL}[/tex]
[tex]= 0.005675 \ mol[/tex]
Mass of BSS in 4.9993 g tablets
[tex]m = 0.005675 \ mol \ Bi^{3+} \times \dfrac{1 \ mol \ BSS}{1 \ mol \Bi^{3+}} \times \dfrac{362.1 \ g \ BSS}{1 \ mol \ BSS}[/tex]
m = 2.055 g BSS
Mass of BSS in 5.0103 g (5 tables)
[tex]m = 2.055 g \ BSS \times \dfrac{5.0103 \ g}{4.9993 \ g}[/tex]
= 2.06 g
∴
The mass of BSS per tablet is [tex]=\dfrac{2.06 \ g}{5 \ tablet}[/tex]
= 0.412 g BSS/ tablet
The following solutions are prepared by dissolving the requisite amount of solute in water to obtain the desired concentrations. Rank the solutions according to their respective osmotic pressures in decreasing order assuming the complete dissociation of ionic compounds. Rank from highest to lowest osmotic pressure. To rank items as equivalent, overlap them.
A. 1 M MgCl2
B. 1 M KCI
C. 1 M C12
D. H22011
1. Highest osmotic pressure
2. Lowest osmotic pressure
Answer: 1. Highest osmotic pressure : 1 M [tex]MgCl_2[/tex]
2. Lowest osmotic pressure: 1 M [tex]C_{12}H_{22}O_{11}[/tex]
Explanation:
[tex]\pi=i\times C\times R\times T[/tex]
[tex]\pi[/tex]= osmotic pressure
i = Van'T Hoff factor
C = concentration
T = Temperature
1. For 1M [tex]MgCl_2[/tex]
, i= 3 as it is a electrolyte and dissociate to give 3 ions.
[tex]MgCl_2\rightarrow Mg^{2+}+2Cl^{-}[/tex]
2. For 1 M [tex]KCl[/tex]
, i= 2 as it is a electrolyte and dissociate to give 2 ions.
[tex]KCl\rightarrow K^{+}+Cl^{-}[/tex]
3. For 1M [tex]C_{12}H_{22}O_{11}[/tex]
, i= 1 as it is a non electrolyte and do not dissociate.
Thus as vant hoff factor is highest for [tex]MgCl_2[/tex] thus osmotic pressure is highest for 1 M [tex]MgCl_2[/tex]
And as vant hoff factor is lowest for [tex]C_{12}H_{22}O_{11}[/tex] thus osmotic pressure is lowest for 1 M [tex]C_{12}H_{22}O_{11}[/tex]
Which of the following are diatomic elements? Select all that apply.
A.Hydrogen
B.Boron
C.Bromine
D.Iodine
Answer:
C
Explanation:
A diatomic element in that list is Bromine
Basic Stoichiometry
Part 1: Mole ←→ Mass Conversions
Choose 2: Convert the following number of moles of chemical into its mass in grams.
1. 0.436 moles of (NH4)Cl = ______g
2. 0.50 moles of Ca(NO3)2 = ______g
Choose 2: Convert the following masses into their corresponding number of moles.
3. 23.5 g of NaCl = ______moles
4. 79.9 g of KMnO4 =______moles
5) The combustion of a sample of butane, C4H10 (lighter fluid), produced 2.46 grams of water.
Answer:
1. 23.3 g
2. 82 g
3. 0.402 mol
4. 0.506 mol
Explanation:
We can convert moles (n) to mass (m) using the following expressions that include the molar mass (M).
n = m/M
m = n × M
1. The molar mass of NH₄Cl is 53.49 g/mol.
m = 0.436 mol × 53.49 g/mol = 23.3 g
2. The molar mass of Ca(NO₃)₂ is 164.09 g/mol.
m = 0.50 mol × 164.09 g/mol = 82 g
3. The molar mass of NaCl is 58.44 g/mol.
n = 23.5 g/(58.44 g/mol) = 0.402 mol
4. The molar mass of KMnO₄ is 158.03 g/mol.
n = 79.9 g/(158.03 g/mol) = 0.506 mol
Methane and sulfur react to produce carbon disulfide (CS₂), a liquid often used in the production of cellophane.
2CH₄ + S₈ --> 2CS₂ + 4H₂S
Calculate the moles of H₂S produced when 2.25 mol S₈ is used.
Answer:
9 moles
Explanation:
The balanced chemical equation provided in this question is as follows:
2CH₄ + S₈ → 2CS₂ + 4H₂S
In accordance to the above balanced equation, 1 mole of sulphur (S8) produces 4 moles of hydrogen sulfide (H2S).
Therefore, if 2.25mol of S8 is used, 2.25 × 4 = 9 mol
9 moles of H2S is produced.
how many grams of silver chloride are produced from 15.0 g of silver nitrate
Answer:
4.2 g
Explanation:
Which halogens are gases at STP?
As the atomic number increases, the reactivity of the halogens decreases. Fluorine and chlorine exist as gases at room temperature, while bromine is a liquid, and iodine is a solid.
Answer:
As the atomic number increases, the reactivity of the halogens decreases. Fluorine and chlorine exist as gases at room temperature, while bromine is a liquid, and iodine is a solid.
Ethanol is a common laboratory solvent and has a density of 0.789 g/mL. What is the mass, in grams, of 133 mL of ethanol?
[tex]V = \text{133 mL}[/tex]
[tex]\rho = \text{0.789 g/mL}[/tex]
Required:[tex]m[/tex]
Solution:[tex]\rho = \frac{m}{V}[/tex]
[tex]m = \rho V[/tex]
[tex]m = (\text{0.789 g/mL})(\text{133 mL})[/tex]
[tex]\boxed{m = \text{105 g}}[/tex]
Ethanol is a common laboratory solvent and has a density of 0.789 g/mL. 105g is the mass, in grams, of 133 mL of ethanol.
What is mass?In physics, mass is a quantitative measurement of inertia, a basic characteristic of all matter. It essentially refers to a body of matter's resistance to changing its speed or location in response to the force that is applied. The change caused by a force applied is smaller the more mass a body has.
The kilogram, which would be specified as equivalent to 6.62× 10³⁴ joule second in terms of Planck's constant, is the unit of mass inside the International Units System (SI).
density = mass / volume
mass =density× volume
= 0.78× 1.33
=105g
Therefore, 105g is the mass.
To know more about mass, here:
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Which of the following has had the most negative effect on Earth's ecosystems?
A. establishment of air pollution standards.
B. increase in human population
C. recycling glass, plastic, and metals
D. use of natural predators to control pest insects.
Answer:
B
Explanation:
humans are evil, done a lot of negative effects on ecosystem.
EDTA is a very common ligand, which like oxalate, binds to many metals. However, unlike oxalate, which forms two bonds, EDTA forms 6 bonds to the metal. A 0.2481g sample of marble was dissolved in 100 mL, and a 10.00 mL aliquot of the solution was titrated to an endpoint with 23.56 mL of 0.01052 M EDTA solution. What is the molecular weight of the marble
Answer:
100 g/mol
Explanation:
The equation of the reaction;
Ca^2+(aq) + EDTA(aq) -----> (CaEDTA)^2-(aq)
Let CA = concentration of EDTA
VA = volume of EDTA
NA= number of moles of EDTA
CB= concentration of marble
VB = volume of marble
NB= number of moles of marble
CAVA/CBVB = NA/NB
CAVANB=CBVBNA
CB = CAVANB/VBNA
CB = 0.01052 * 23.56 * 1/10.00 * 1
CB = 0.02479 M
number of moles = concentration * volume
number of moles = 0.02479 M * 100.00/1000L
number of moles = 2.479 * 10^-3 moles
number of moles = mass/molar mass
molar mass = 0.2481g/2.479 * 10^-3 moles
molar mass = 100 g/mol
The strength of an acid is affected by the polarity of the bond connected to the acidic hydrogen. The more highly polarized this bond, the more easily the hydrogen is ionized. Electronegative atoms or groups of atoms present in the structure of an acid can act to withdraw electrons and produce additional polarization. Two common groups of acids to which this principle can be applied are oxoacids and carboxylic acids. In the latter group, the length of the hydrocarbon chain in a carboxylic acid has very little effect on acid strength Longer chains may slightly diminish acidity. Bases act as hydrogen ion acceptors because of the unshared electron pass in their structure. Any group present in a base that withdraws electrons makes these electron pairs less available to accept a hydrogen ion. In contrast, any group that can act as an electron donating group such as hydrocarbon groups (usually represented as II) can increase the base strength. Thus, the addition of electronegative atoms or groups of atoms to the structure of a base decreases the base strength and electron donating groups increase base strength. Many common weak bases are derivatives of ammonia, in which H atom(s) of NH_2 are replaced with other groups.
Arrange the following oxoacids in order of decreasing acid strength. Rank from strongest to weakest acid.
HBrO
HClO
HClO3
HClO2
Answer:
HClO3>HClO2>HClO>HBrO
Explanation:
Hello there!
In this case, in agreement to the given information and the reported acidic dissociation constant (Ka) for these acids, which are shown below:
[tex]Ka_{HBrO}=2x10^{-9}\\\\Ka_{HClO}=3.5x10^{-8}\\\\Ka_{HClO_2}=1.2x10^{-2}\\\\Ka_{HClO_3}>>>>1[/tex]
In such a way, since the Ka of chloric acid, HClO3 is greater than 1, we infer it is a strong acid so it is the strongest, next we have HClO2, then HClO and the weakest would be HBrO as its Ka is the smallest.
Thus, the order would be:
HClO3>HClO2>HClO>HBrO
Best regards!
how is acid different from base
Plz help me I am timed!!
Answer:
What do you need help with
Explanation:
Explanation:
okay I'll help but whats the question
Tam a highly reactive alkali metal in period 3 with only one valence electron
O Sodium (Na)
Beryllium (Be)
Magnesium (Mg)
Answer:
Sodium (Na)
Helium
Magnesium (Mg).
Explanation:
From the periodic table, we will understand that the group 1 metals are the alkali metal. However, the period runs from left to right on the periodic table while the group runs from up to down in the periodic table. In period 3, the alkali metal present there with one valence electron in its outermost shell is sodium (Na).
The only noble gas exists in the last group, group zero of the periodic table. However, the only noble gas with two electrons in its outermost shell is called Helium
The ALkaline earth metals are group 2 metals. They are usually shiny metals and the ability to lose 2 electrons in their outermost electron shell. The alkaline earth metal located in period 3 is Magnesium (Mg).
At which point on the roller coaster will the car have the greatest amount of Kinetic energy?
Which expression represents the concentration of OH– in solution?
a. 10–14 / [H3O+]
b. [OH–] / 10–14
c. 10–14 – [H3O+]
d. 10–14 x [H3O+]
