Answer:
c) lenght/distance
Explanation:
Metric units are mostly used in Europe (centimeters and meters instead of inches and feet)
Answer:
c. length / distance
Two isotopes of potassium are K-37 and K-42. Explain, in terms of subatomic particles, why K-37
and K-42 are isotopes of potassium.
Richard and Brooke's teacher tells them to place 30 marbles in an 8-inch
baking pan to make a model. She tells them that each marble represents
a water molecule in the liquid state. Then she asks them to move their
model to show what happens to the liquid water molecules when heat is
added. What do Richard and Brooke do to show this?
They spread the marbles to the edges with their hands.
They tilt the pan so the marbles move to one side of the pan.
They push the marbles to the center of the pan with their hands
They gently shake the pan causing the marbles to move back and forth.
Answer:
The correct answer is - They gently shake the pan causing the marbles to move back and forth.
Explanation:
When water is heated the molecules present in its liquid state start to move and vibrate faster and allows the water to expand and increase in volume. If the heat is continuously applied to the water its molecules move even faster and escape in the form of molecules of vapor to the atmosphere.
To exhibit this phenomenon by the marble and pan, Richard and Brooke should gently shake the pan causing the marbles to move back and forth which shows faster vibration and movement of molecules.
I am playing with my
Answer:
wow ok have fun
Explanation:
Answer:
hiiiiiiiii
Explanation:
thank you
5(a) Consider the following schemes
Petroleum
>petroleum fractions
Higher petroleum fractions 1 , petrol + x
X + Y MI >CH,CICH,CI
nX"V (CH2 - CH2 - CH2-CH2)n
(i) State the type of reaction involved in I to IV
Answer:
is number 1
Explanation:
cause i know
type of reproduction taking place with one parent
how many molecules are in 2h2o2
Answer:
I think 7, 4, 6, or 8
I think that one of those is correct
Explanation:
please its urgent! 8P4 + 3S8 -> 8P4S3
The molar masses of the substances are as follows: P4 = 123.895g/mol, S8 = 256g/mol, P4S3 = 220.093g/mol
If 20.0g of P4 and 40.0g of S8 are combined, what is the amount of P4S3 produced in moles?
Answer:
The amount of P₄S₃ produced is 0.16 moles.
Explanation:
The balanced reaction is:
8 P₄ + 3 S₈ → 8 P₄S₃
By stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of each compound participate:
P₄: 8 moles S₈: 3 moles P₄S₃: 8 molesBeing the molar mass of each compound:
P₄: 123.895 g/molS₈: 256 g/mol P₄S₃: 220.093 g/molthen by stoichiometry of the reaction, the following amounts of reactant and product participate in the reaction:
P₄: 8 moles* 123.895 g/mol= 991.16 gS₈: 3 moles* 256 g/mol= 768 gP₄S₃: 8 moles* 220.093 g/mol= 1,760.744 gThe limiting reagent is one that is consumed first in its entirety, determining the amount of product in the reaction. When the limiting reagent is finished, the chemical reaction will stop.
In this case, you calculate the limiting reactant using the following rule of three: if by stoichiometry 768 g of S₈ react with 991.16 g of P₄, 40 g of S₈ with how much mass of P₄ will it react?
[tex]mass of P_{4}=\frac{40 grams of S_{8} *991.16 grams of P_{4} }{768 grams of S_{8}}[/tex]
mass of P₄= 51.62 grams
But 51.62 grams of P₄ are not available, 20 grams are available. Since you have less mass than you need to react with 40 grams of S₈, P₄ will be the limiting reagent.
Then you can apply the following rule of three: if by stoichiometry 991.16 grams of P₄ form 8 moles of P₄S₃, 20 grams of P₄ will form how many moles of P₄S₃?
[tex]moles of P_{4} S_{3}=\frac{20 grams of P_{4} *8 moles ofP_{4} S_{3} }{991.16 grams of P_{4}}[/tex]
moles of P₄S₃= 0.16
The amount of P₄S₃ produced is 0.16 moles.
The formula StartFraction actual yield over theoretical yield EndFraction. is used to calculate the ____ yield of a reaction.
Answer:
Percentage yield
Explanation:
The formula given in question above is used to calculate the percentage yield.
The percentage yield of a given reaction is defined as the value obtained in percent by comparing the actual and theoretical yield together. It can be obtained by using the following formula:
Percentage yield = (Actual / Theoretical) × 100
Where:
The actual yield is the mass obtained from the experiment. The theoretical yield is the mass obtained from the stoichiometric calculations.Learn more about percentage yield: https://brainly.com/question/25910524
what is one reason why we use salt in cooking
Answer:
It's used as a seasoning for the taste of food. It also helps to bring out the natural flavours in the food.
How many grams of lithium chloride, molecular mass 42.5, are dissolved in water to make 500 mL of a 0.450 M solution?
A) 9.56g
B) 42.50g
C)21.25g
D)47.22g
Answer:
9.5625 gram
Explanation:
Molarity = mass in gram ÷ molar mass × volume in dm3
Mass in gram = molarity× molar mass × volume of solution in dm3
Mass in gram = 0.450×42.5×0.5=9.5625 g
Why concentrated HNO3 is 69% by mass of nitric acid? Please explain what it means.
Answer:
See the answer below
Explanation:
The percentage by mass of a substance in a mixture is the ratio of the mass of the substance and the mass of the entire mixture.
Hence, when concentrated HNO3 is said to be 69% by mass of nitric acid, it means that the solution of the acid has 69% HNO3 and 31% water in terms of mass. More specifically, 100 g of the solution of the acid would contain 69 g of HNO3 and 31 g of water respectively,
I need help tutor it is hard
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Microwave radiation has a wavelength on the order of 1.0 cm. Calculate the frequency and the energy of a single photon of this radiation. Calculate the energy of an Avogadro's number of photons (called as einstein) of this radiation.
Given that,
The wavelength of microwave radiation = 1 cm = 0.01 m
To find,
The frequency and the energy of a single photon of this radiation.
Solution,
Let f be the frequency of the wave. The relation between frequency and wavelength is given by :
[tex]f=\dfrac{c}{\lambda}\\\\f=\dfrac{3\times 10^8}{0.01}\\\\=3\times 10^{10}\ Hz[/tex]
Let E be the energy of the wave. The energy of the wave is given by :
[tex]E=hf\\\\=6.63\times 10^{-34}\times 3\times 10^{10}\\\\=1.98\times 10^{-23}\ J[/tex]
We know that, [tex]N_A=6.022\times 10^{23}\ \text{photons/mol}[/tex]
Energy :
[tex]E={1.98\times 10^{-23}}\times {6.023\times 10^{23}}\\\\=11.92\ J/mol[/tex]
Hence, this is the required solution.
Which statement describes the Arrhenius interpretation of acids and bases?
It has a wider range of applications than the Bronsted-Lowry interpretation.
It has a wider range of applications than the Lewis and Bronsted-Lowry interpretations.
It is used in situations that involve bases that do not produce hydroxide ions.
It is limited to situations that involve aqueous solutions or specific compounds.
Answer:
D. It is limited to situations that involve aqueous solutions or specific compounds.
Explanation:
It is the only interpretation that involves specifically aqueous solutions.
The statement that describe Arrhneius interpretation of acids and bases is It is limited to situations that involve aqueous solutions or specific compounds.
Arrhenius interpretations of acids and bases.Svante Arrhenius a swedish scientist formulated a theory about acid and bases in 1884 based on theory of ionization. Arrhenius stated that acids contains hydrogen ions and when its dissociates in water will give out H+ ions and base is an hydroxide substances that will produce OH− ions on when it dissociates in water.
Therefore, The statement that describe Arrhneius interpretation of acids and bases is It is limited to situations that involve aqueous solutions or specific compounds.
Learn more about Arrhneius interpretation of acids and bases
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how to you distinguish dilute nitric acid and concentrated nitric acid using chemical methods?
Answer:
I have two methods to distinguish between concentrated and dilute nitric acid
Method 1: Using magnesium/manganese.
Mg + 2HNO₃ (1%) → Mg(NO₃) + H₂
very very dilute
Mg + 4HNO₃ → Mg(NO₃)+ 2H₂O +2NO₂
concentrated
In the first reaction of magnesium with concentrated nitric acid, hydrogen is evolved.
In the second reaction of magnesium with very very dilute nitric acid, water is evolved.
Using the respective tests for hydrogen and water, we can test them.
Method 2: Using iron.
3 Fe + 8HNO₃→ 3Fe(NO₃)₂ + 4H₂O + 2NO
dilute
Fe + 6HNO₃→ Fe(NO₃)₃ + 3H₂O + 3NO₂
concentrated
In the first case of method 2,
Fe(NO₃)₂ ⇆ Fe²⁺ + (NO₃) ⁻ Iron with valency 2+ is formed
In the second case of method 2,
Fe(NO₃)₃ ⇄ Fe³⁺ + (NO₃) ⁻ Iron with valency 3+ is formed
Brainlist pls!
What is a reduction reaction?
A. A reaction in which an atom forms a new isotope by gaining neutrons.
B. A reaction in which charged particles form an ionic compound.
C. A reaction in which negatively charged particles are in the products.
D. A reaction in which an atom has gained 1 or more electrons.
Answer:
D. A reaction in which an atom has gained 1 or more electrons.
Explanation:
The oxidation reduction reactions are called redox reaction. These reactions are take place by gaining or losing the electrons and oxidation state of elements are changed.
Oxidation:
Oxidation involve the removal of electrons and oxidation state of atom of an element is increased.
Reduction:
Reduction involve the gain of electron and oxidation number is decreased.
Consider the following reactions.
4KI + 2CuCl₂ → 2CuI + I₂ + 4KCl
The oxidation state of copper is changed from +2 to +1 so copper get reduced by gaining the one more electron
What are the physical and chemical properties of compounds most influenced by?
As the names suggest, a physical change affects a substance's physical properties, and a chemical change affects its chemical properties. Many physical changes are reversible (such as heating and cooling), whereas chemical changes are often irreversible or only reversible with an additional chemical change.
(hope this helps ^^)
12. Which one of the following is not true about the reaction of: CH3-CH3+Cl2...CH3CH2Cl+HCl? * *
it is elimination reaction
it is photochemical reaction
it is chlorination reaction
it is substitution reaction
Answer:
it is elimination reaction
Explanation:
Because substitution takes place not elimination
Give reasons:
(a) Winding roads are made on hills.
Answer:
Mountainous roads are winding and gently sloping in order to reduce the effect of steepness which causes more downward gravitational pull to the vehicles on it. A steeper sloped road would slow the car down to a greater extent that an gently sloping one.
A classmate is arguing that when someone is sick with the flu, the immune system works with the skeletal system to fight against diseases. Do you agree or disagree and why.
A.
I agree, the skeletal system helps the immune system by producing white blood cells which are used to fight against infection.
B.
I disagree, the skeletal system only provides support and protection for the body whereas the immune system fights against diseases.
C.
I disagree, the skeletal system fights against diseases without the help of the immune system.
D.
I agree, the skeletal system helps the immune system by breaking down nutrients to supply the white blood cells with energy.
Answer:
c
Explanation: i am for sure
A diver dives off a 32-meter high diving board into
the water below. If the diver pushes off with an initial
horizontal velocity of 1.2 m/s, how far from the base
of the board does she land?
Answer:
3.06 m
Explanation:
Time of fall be t .
h = ut + 1/2 g t² , h is height , u is initial vertical velocity = 0
h = 1/2 g t²
32 = .5 x 9.8 x t²
t = 2.55 s
During this period , diver will move in horizontal direction also .
Horizontal displacement during fall
= horizontal velocity x time
= 1.2 x 2.55
= 3.06 m
What is the gram formula mass of K?
Answer:
6.4924249 × 10^-23 g you need to solve it
HELP PLEAAAAAAASE!!!!!
As the radius of a star increases, how do you think its luminosity might change?
what does a net ionic equation show about a reaction
Answer:
A net ionic equation shows only the chemical species that are involved in a reaction, while a complete ionic equation also includes the spectator ions.
Brainlist pls!
The carbon atom has six total electrons in two energy levels. How many will be in each
level?
Answer:
5
Explanation:
Answer:
2 in the first and 4 in the second
Explanation:
in an atom the first energy level has only 2 spaces for electrons, as the number electrons goes up so does the amount of energy levels
Nitric acid with a concentration of 1mol/dm has a pH
A student diluted 25cm of the acid with same volume of water.
What effect would this have on the pH of the acid?
hey so i dont get this help please
Answer:
ta da
Explanation:
In the reaction 2Na+ Cl2 + 2NaCl, the products are O half the reactants. twice the reactants. the same as the reactants. o different from the reactants.
Answer:
It should be the same as the reactants. Because there is no loss or replacements.
Explanation:
Answer:
The same as the reactants
Explanation:
8 As a bee feeds upon the nectar produced by a flower, the bee may become coated with the flower's pollen. As the bee flies from flower to flower, some of this pollen may contact a flower's pistil, resulting in pollination. This relationship between the bee and the flower is an example of _______.
Answer:
nector
Explanation:
Which characteristic do all organisms as share
Answer: All living organisms share several key characteristics: sensitivity or response to the environment, reproduction, growth and development, regulation, homeostasis, and energy processing.