Answer:
D. Halogens
Explanation:
All elements in these groups have 7 valence electrons, meaning their electronegativity is the highest among the elements.
At night, the demand for electricity supplied by a fission nuclear reactor decreases. How is the fission nuclear reaction controlled to avoid overproduction of electricity? The temperature of the reactor is lowered because high temperature and pressure are needed. The temperature of the reactor is raised because the reaction slows down at higher temperatures. The exposure between the fuel rods and a neutron-absorbing material is increased. The exposure between the fuel rods and a neutron-absorbing material is reduced.
Answer:
The exposure between the fuel rods and a neutron-absorbing material is increased.
Explanation:
The exposure between the fuel rods and a neutron-absorbing material is increased.
A nuclear reactor produces energy via a fission reaction. A fission reaction is a self sustaining reaction.
The nuclear fuel is bombarded with neutrons. The process produces more neutrons which continues the reaction.
In order to decrease the rate of reaction, control rods are inserted. These control rods are neutron-absorbing materials.
At night when demand for electricity decreases, the exposure between the fuel rods and a neutron-absorbing material is increased so that more neutrons are absorbed in order to decrease the rate of nuclear reaction.
Copper carbonate (CuCO3) reacts with hydrochloric acid (HCl) according to this equation:
CuCO3(s) + 2HCl(aq) → CuCl2(aq) + H2O(l) + CO2(g).
Which statement correctly describes the substances in this reaction?
A.
Exactly one product and two reactants are either liquid or dissolved in water.
B.
Exactly one of the reactants is in a water-based solution, but none of the products are.
C.
The reactants include both a liquid and a gas.
D.
Exactly one reactant is a solid, and exactly one product is a gas.
E.
The products include a solid, a liquid, and a gas.
Answer: D. Exactly one reactant is a solid, and exactly one product is a gas.
Explanation: PLATO
In the given reaction, there is only one reactant in solid state, that is copper carbonate and one gaseous product carbon dioxide. Hence, option D is the correct statement.
What is copper carbonate?Copper carbonate is an ionic compound formed by the combination of copper metal and carbonate group. Copper metal loses two electrons to the carbonate group. It is a white powder and sparingly soluble in water.
The states of reactants and products in a reaction is represented in brackets with the chemical formula of each compound. The reaction in which all the reactants are in same phase is called homogeneous.
The given reaction is an example of heterogeneous replacement reaction. The reaction includes the combination of solid copper carbonate with aqueous HCl giving copper chloride solution and carbon dioxide gas. Thus, option D is correct.
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What is the law of conservation of energy? a. Energy is created and destroyed. b. Energy is not created but is destroyed. c. Energy is created but not destroyed. d. Energy is neither created nor destroyed pls help
Answer:
Energy is neither created nor destroyed.
Explanation:
The law of conservation of energy states that energy can neither be created nor be destroyed. The total energy of an isolated system remains conserved. It never gets 0. It changes from one form of energy to other but never vanishes.
Hence, the correct option is (d) "Energy is neither created nor destroyed"
Please help correct answers only please
Answer:
Empirical formula is C₅H₁₂O
Molecular formula = C₅H₁₂O
Explanation:
Given data:
Percentage of hydrogen =13.75%
Percentage of carbon = 68.11%
Percentage of oxygen = 18.15%
Empirical formula = ?
Solution:
Number of gram atoms of H = 13.75 / 1.01 = 13.6
Number of gram atoms of O = 18.15 / 16 = 1.13
Number of gram atoms of C = 68.11 / 12 = 5.68
Atomic ratio:
C : H : O
5.68/1.13 : 13.6/1.13 : 1.13/1.13
5 : 12 : 1
C : H : O = 5 : 12 : 1
Empirical formula is C₅H₁₂O.
Molecular formula:
Molecular formula = n (empirical formula)
n = molar mass of compound / empirical formula mass
Empirical formula mass :
5×12 + 12×1.01 + 16×1 = 88.12 g/mol
n = 88.17/ 88.12
n = 1
Molecular formula = n (empirical formula)
Molecular formula = 1 (C₅H₁₂O)
Molecular formula = C₅H₁₂O
x-rays had a frequency of about 3x10^18 determine it's wavelength (in nm) and energy per photon
Answer:
E = 19.89×10⁻¹⁶ J
λ = 1×10⁻¹ nm
Explanation:
Given data:
Frequency of xray = 3×10¹⁸ Hz
Wavelength of xray = ?
Energy of xray = ?
Solution:
speed of wave = wavelength × frequency
speed = 3×10⁸ m/s
3×10⁸ m/s = λ ×3×10¹⁸ s⁻¹
λ = 3×10⁸ m/s / 3×10¹⁸ s⁻¹
λ = 1×10⁻¹⁰m
m to nm:
λ = 1×10⁻¹⁰m×10⁹
λ = 1×10⁻¹ nm
Energy of x-ray:
E = h.f
h = plancks constant = 6.63×10⁻³⁴ Js
by putting values,
E = 6.63×10⁻³⁴ Js ×3×10¹⁸ s⁻ ¹
E = 19.89×10⁻¹⁶ J
In your home, you can turn off your television set but all of your other appliances will stay on. This is because the appliances in your home are connected *
in series
in parallel
Well
Together
Answer:
in parallel
Explanation:
All of the home equipment in the residence are linked in parallel.
Are domestic appliances linked in collection or parallel?parallel association
electric appliances are connected in a parallel arrangement in a house circuit because every appliance gets complete voltage as resistance in a parallel association is low.
Why are electrical appliances in our household no longer connected in collection?electric appliances are not linked in series because the cutting-edge can be the same thru all the home equipment connected but voltage increases if extra no. Of appliances are related. If the battery has low voltage than the full voltage it can short circuit.
research greater approximately the parallel.
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please help out correct answers only
Answer:
Molecular formula = SF₆
Empirical formula is SF₆
Explanation:
Percentage of sulfur = 21.95%
Percentage of fluorine = 78.03%
Molar mass of compound = 146.1 g/mol
Empirical formula = ?
Molecular formula = ?
Solution:
Number of gram atoms of S = 21.95 / 32= 0.69
Number of gram atoms of F = 78.03 / 19 = 4.107
Atomic ratio:
S : F
0.69/0.69 : 4.107/0.69
1 : 6
S : F = 1:6
Empirical formula is SF₆
Molecular formula:
Molecular formula = n (empirical formula)
n = molar mass of compound / empirical formula mass
Empirical formula mass :
32 + 19×6 = 146
n = 146.1 / 146
n = 1
Molecular formula = n (empirical formula)
Molecular formula = 1 (SF₆)
Molecular formula = SF₆
The climate in the temperate deciduous forest biome has four changing seasons with rain.
True
False
Why does a chemical equation be balanced?
Answer:
Law of conservation of matter
Explanation:
guys, how do i know whether the forces of attraction is strong or weak?
Answer:
Whether the forces of attraction is strong or weak is explained below in details.
Explanation:
There are three distinct kinds of intermolecular forces in expressions of energy. They are (strongest to weakest) dipole-dipole, hydrogen bonding, and Van der Waals' strengths. Intermolecular forces are weak related to intramolecular forces – the energies which endure a molecule collectively. For instance, the covalent bond, including distributing electron sets among atoms, is much more powerful than the forces impersonate among neighboring molecules.
A cone has a diameter of 4 inches and a height of 7 inches. Find the volume
of the cone. Use 3.14 for II.
Volume of a cone: II rh
177.2 in.
29.3 in.3
351.7 in.
87.9 in.
Answer:
V = 29.3 inch³
Explanation:
Given data:
Diameter of cone = 4 inch
Height of cone = 7 inch
Volume of cone = ?
Solution:
Formula:
V = πr²h/3
we calculate the radius from diameter,
r = 4 inch/2 = 2 inch
Volume:
V = 3.14 ×(2 inch)² × 7 inch/3
V = 3.14 × 4 inch² × 7 inch/3
V = 29.3 inch³
How many moles of sulfur trioxide are formed from 3 moles of oxygen using the given
balanced equation?
2 SO. +0,- 2 so.
Answer:
6 moles of SO₃ formed.
Explanation:
Given data:
Number of moles of SO₃ formed = ?
Number of moles of oxygen react = 3 mol
Solution:
Chemical equation;
2SO₂+ O₂ → 2SO₃
now we will compare the moles of oxygen and sulfur trioxide.
O₂ : SO₃
1 : 2
3 : 2/1×3 = 6 moles
Thus, six moles of SO₃ will formed.
What is responsible for the blue sky?
Answer:
Gasses and particles in Earth's atmosphere scatter sunlight in all directions. Blue light is scattered more than other colors because it travels as shorter smaller waves. This it why we see a blue sky most of the time
Explanation:
I looked it up
Answer:
sun shine
Explanation:
A clear cloudless day-time sky is blue because molecules in the air scatter blue light from the sun more than they scatter red light. When we look towards the sun at sunset, we see red and orange colours because the blue light has been scattered out and away from the line of sight.
The table below shows the elements that mainly comprise each of the four layers of Earth:
Elements in Layers
Layer Main Elements
Crust Oxygen, Silicon
Mantle Iron, Magnesium
Outer Core Iron, Nickel
Inner Core Iron
Which of these elements make up the layer that is 0.2 to 1.1 percent of Earth's total diameter?
Magnesium and Silicon
Iron and Magnesium
Iron and Nickel
Oxygen and Silicon
Answer:
The answer is oxygen and silicon
Explanation:
I took the test and it was right
The answer is oxygen and silicon
What contribution did Niels Bohr make to atomic theory
Answer:
Bohr's greatest contribution to modern physics was the atomic model. The Bohr model shows the atom as a small, positively charged nucleus surrounded by orbiting electrons.
Explanation:
Answer: He proposed a theory for the hydrogen atom based on quantum theory
Explanation:
3. What determines that an element is a metal?
Answer:
if it forms from positive ions and has types of metallic bonds
Explanation:
what is th correct chemical symbol for nitrogen
Answer:
The correct symbol for Nitrogen is N.
Explanation:
I do A P E X.
What are food molecules made out of?
Answer:
Most foods are made out of carbon, oxygen, nitrogen and hydrogen
Explanation:
100 cm3 of hydrogen is mixed with 25 cm3 of oxygen at a temperature of 150qC. The gases react as shown in the equation below. 2H2(g)+ O2(g) o 2H2O(g) The total volume of gas present at the end of the reaction is A 50 cm3 B 100 cm3 C 125 cm3 D 150 cm
Answer:
B 100 cm3
Explanation:
The balanced equation is given as;
2H2(g)+ O2(g) --> 2H2O(g)
From the reaction stochiometry, 2 cm3 of H2 would react with 1 cm3 of O2 to form 2 cm3 of H2O
Before Reaction --> 100cm3 of H2, 25cm3 of O2, 0cm3 of H2O
During Reaction --> 50cm3 of H2, 25cm3 of O2, 50cm3 of H2O
(Oxygen is sed uup in the reaction)
After Reaction --> 50cm3 of H2, 0cm3 of O2, 50cm3 of H2O
Total volume left = Unreacted H2 (50cm3) + 50cm3 of H2O formed
Total Volume left = 50 + 50 = 100cm3
The total volume of gas present at the end of the reaction is 100 cm³
What is a chemical reaction?a process that involves rearrangement of the molecular or ionic structure of a substance, as distinct from a change in physical form or a nuclear reaction.
The balanced equation is given as;
2H₂(g)+ O₂(g) → 2H₂O(g)
From the reaction stoichiometry, 2 moles of H₂ would react with 1 mole of O₂ to form 2 moles of H₂O
Before Reaction: 100cm³ of H₂, 25cm³ of O₂, 0cm³ of H₂O
During Reaction: 50cm³ of H₂, 25cm³ of O₂, 50cm³ of H₂O
(Oxygen is used up in the reaction)
After Reaction: 50cm³ of H₂, 0cm³ of O₂, 50cm³ of H₂O
Total volume left = Unreacted H₂ (50cm³) + 50cm³ of H₂O formed
Total Volume left = 50 + 50 = 100cm³
Hence, The total volume of gas present at the end of the reaction is 100 cm³
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One can find the pH of a substance by using ___.
A. a conductivity tester
B. a thermometer
C. plain paper indicator
D. litmus paper indicator
Explanation:
C. Plain paper indicator.
Litmus paper indcator can only tell you if the solution is acidic/neutral/alkaline, but not to what extent.
Hi! Can you help me?
Is NaCI an element, compound, or mixture?
Thanks!
Answer:
Compound
Explanation:
Sodium chloride, commonly known as salt, is an ionic compound with the chemical formula NaCl, representing a 1:1 ratio of sodium and chloride ions. With molar masses of 22.99 and 35.45 g/mol respectively, 100 g of NaCl contains 39.34 g Na and 60.66 g Cl
The recessive allele tends to (blank) when it's in the presence of the dominant allele.
Answer:
The recessive allele tends to be masked when it's in the presence of the dominant allele.
Explanation:
Many of our traits are affected by our genes. From each of our parents, we receive one copy of every gene. These copies are called alleles.
There are different types of relationships that can occur between alleles. One of them is called dominance. This occurs when one allele masks the other, not allowing its effect to be expressed. The allele that masks the other is called the dominant allele (A), and the masked one is called the recessive allele (a). This means that an individual needs to have only one dominant allele in order for its effect to be expressed (AA or Aa). The effect of the recessive allele will be expressed only when an individual has both recessive alleles (aa).
HELP PLEASE ASAAPPP!!!How many atoms of silicon would there be in a sample that contained 4.66 x 1030
grams? ANSWER CHOICES INCLUDED IN IMAGE ABOVE
Answer:
there is no image
Explanation:
can you maybe ask the question again with the image?
Answer:
put an image please i don't understand
which best explains why estuaries are an important habit for many Marine organisms in comparison to the open ocean?
A) there is less food in the estuaries
B) there are more predators in estuaries
C) there is more salt available in estuaries
D) there are more nutrients available in estuaries
which best explains why estuaries are an important habit for many Marine organisms in comparison to the open ocean?
Answer:-there are more nutrients available in estuaries
Extra information:-Open ocean:-The Open ocean is also known as pelagic zone.It is the area of the ocean which is outside of coastal areas. The open ocean lies over the continental shelf. The seafloor is not included in the open ocean.why is the separation of waste rock before mining so important?
Answer:
because the minerals in the rock can't be used until they are separated
Select all the correct answers.
In this reaction, how does the rate of forward reaction vary with the concentration of the product?
2H,S() =2H() + S(g)
O It increases with an increase in the concentration of S-(g).
OIt decreases with a decrease in the concentration of H().
OIt increases with a decrease in the concentration of H-(g).
It decreases with an increase in the concentration of S,().
It decreases with increase in the concentration of Ha().
The correct answers :
It increases with a decrease in the concentration of H₂(g).
It decreases with an increase in the concentration of S₂(g).
It decreases with an increase in the concentration of H₂(g).
Further explanationForward reaction : rate to form product
In equilibrium :
The product decreases ⇒ system will move from left to right(forward reaction)
The product increases ⇒ system will move from right to left(reverse reaction)
(0)A mixture of dihydrogen and dioxygen at one bar pressure contains 70% by weight of dioxygen. Calculate the partial pressure of dioxygen.
a (ii)Calculate the volume occupied by 8.8 g of CO2 at 31.1°C and 1 bar pressure. R = 0.083 bar L K-1 mol-1
Answer:
a) 0.13 bar
b) 5.05 L
Explanation:
Let us take the mass of the mixture to be 100 g. Hence, 70% by weight of dioxygen corresponds to 70 g
Mass of dihydrogen = 100g - 70 g = 30g
Number of moles of dioxygen = 70g/32 g/mol = 2.2 moles of dioxygen
Number of moles of dihydrogen = 30g/2g/mol = 15 moles of dihydrogen
Total number of moles = 2.2 + 15 = 17.2 moles
Mole fraction of dioxygen = 2.2/17.2 = 0.13
Partial pressure = mole fraction * total pressure
Partial pressure of dioxygen = 0.13 * 1 = 0.13 bar
ii) number of moles in 8.8 g of CO2 = 8.8g/44g/mol = 0.2 moles
T = 31.1 + 273 = 304.1 K
P = 1 bar
V= ?
R = 0.083 bar L K-1 mol-1
From
PV=nRT
V = nRT/P
V= 0.2 * 0.083 * 304.1/1
V= 5.05 L
Which diagram shows an element?
give two example for desert plants and animals?
please mark as brainliest
Answer:
Plants : Cactus, tumbleweed
Animals : camel, fennec fox
Answer:
Desert plant - Cactus & Tumbleweed
Desert animal - Camel & Scorpion
(30 points) Ahhhhhhh can someone help me :'))
I'm not smart and I don't understand how to solve this problem:
Octane, one of the major components of gasoline, burns in air according to this unbalanced equation:
C₈H₁₈ (l) + O₂ (g) ----> CO₂ (g) +H₂O
The formula balanced is: 2 C₈H₁₈ (l) + 50 O₂ (g) ----> 16 CO₂ (g) + 18 H₂O
a) What volume of O₂ at STP is needed to burn 702g (1.00L) of octane?
b) What volume of O₂ at 18°C and 0.975 atm is needed to burn 702g of octane?
Answer:
a. 137.93 dm3
b. 150.61 L
Answer:
C₈H₁₈
Explanation:
