Answer:
a chemical change is correct answer
Is combining baking soda and shaving cream a chemical or physical change? It doesn't have to be for today, but please help!
Answer:
it's chemical
Explanation:
In your own words, define the following terms.
1 Blood
2 Lymph
3 Alveoli
Answer:
BLOOD - the definition of blood is the fluid carries oxygen
Explanation:
sana po makatulong♡♡
A. 207 kJ
B. 4730 kJ
C. 9460 kJ
D. 414 kJ
Answer:
Q = 9460 Kj
Explanation:
Given data:
Mass of copper = 2kg
Latent heat of vaporization = 4730 Kj/Kg
Energy required to vaporize 2kg copper = ?
Solution:
Equation
Q= mLvap
It is given that heat required to vaporize the one kilogram copper is 4730 Kj thus, for 2 kg
by putting values,
Q= 2kg × 4730 Kj/Kg
Q = 9460 Kj
relation between atomic number and frequency of radiation
Answer:
This law established a relationship between atomic number of element and frequency of X-rays of that atom. According to this law, the square root of frequency of X-rays imparted by elements is directly proportional to the atomic number of that element.
A self-contained system within a larger system? *
Answer:
subsystems.
Explanation:
A self-contained system within a larger system. system. A group of interacting or interdependent elements forming a complex whole, as in all the factors or variables in an environment or all the variables that might affect a science experiment.
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Question 13 / 40
When electrons move from a high energy level to a low energy level, which of the following statements are correct?
spectral lines are emitted
mass is converted to energy
the photoelectric effect occurs
quarks combine to create subatomic particle
Answer:
Explanation:
Mass is converted to energy
1. Mixing is a physical change.
True or false
Answer:
false it is a chemical change
. Now Sara comes along, and she is the exact same size as you. However, she is even stronger than you are! When she pulls you in the wagon, she pulls with a greater force than when you pull her. Now who is in the wagon when it has the greatest acceleration? Explain, using Newton's second law. Sara would win because she is stronger but we have the same force.
Answer:
See explanation
Explanation:
According to Newton's second law, the rate of change of momentum is proportional to the impressed force.
Mathematically;
Ft = mv - mu
Where;
F = Force
t = time
m= mass
v = final velocity
u = initial velocity
Since the mass is the same, the equation reduces to;
Ft = m(v-u)
So
F= m(v-u)/t
but
(v-u)/t = acceleration (a)
F = ma
a = F/m
Since the mass is the same because Sarah is the same size as i am but she pulls with a greater force, it follows that i will be the one in the wagon when the wagon has the greatest acceleration because the force that Sarah applies when pulling me is greater than the force i will apply when pulling her.
........PLEASE HELP........
Why does oxygen have stronger attractive forces between its nucleus and valence electrons than nitrogen?
The energy required to overcome the attraction between two bonded nuclei and their shared electrons is called _____ energy. This quantity is a measure of bond strength since the stronger the bond, the _____ the amount of energy required to break it.
Answer:
Nuclear Binding Energy (Bond Energy), Higher (Greater)
Explanation:
The energy required to overcome the attraction between two bonded nuclei and their shared electrons is called Nuclear Binding Energy (Bond Energy). This quantity is a measure of bond strength since the stronger the bond, the Higher (Greater) the amount of energy required to break it.
The energy required to overcome the attraction between two bonded nuclei and their shared electrons is called bond energy. This quantity is a measure of bond strength since the stronger the bond, the greater amount of energy required to break it.
I hope this helps!
What does percent composition tell you about a molecule?
A. It tells you how much of a molecule is made up of each element.
B. It tells you the ratio of elements in the molecular formula.
C. It gives you the total number of atoms in the molecule.
D. It tells you how the lements are arranged in the molecule.
Answer:
a
Explanation:
what kinds of bonds are found in a sample of H2O(s)?
Answer:
a covalent bond? is that what you mean?
Explanation:
En un recipiente cerrado a 25°C disponemos de un gas sometido a una presión de 250.000 Pa. Luego, sin que cambie el volumen, conseguimos una presión de 350.000 Pa. ¿a qué temperatura habremos tenido que calentar el gas?.
Answer:
El gas se calentó a 35°C
Explanation:
Para resolver este problema es necesario aplicar la Ley de Gay Lussac donde en una situación en la que un gas no modifica su volumen, su temperatura será directamente proporcional a la presión.
Podemos pensar que se describe desde la Ley de Gases Ideales donde:
P . V = n . R . T
para la situacion 1
y P . V = n . R . T para la situacion 2
Como V, n y R son constantes:
P₁ / T₁ = P₂ / T₂
250000 Pa / 25°C = 350000 Pa / T₂
T₂ = 350000 Pa . 25°C / 250000 Pa → 35°C
What is the final volume of the ballon after it has been placed in a hot room
Answer:
The Answer is 2.1
Hope this helps!
formula of preparation of sodium hydroxide
The chemical formula of sodium hydroxide is NaOH, and its molar mass is 40.01 g/mol. It is the alkali salt of sodium, and its structure is shown below:
It is an ionic compound consisting of sodium cation (Na+) and hydroxide (OH-) anion.
If the grass contains 220,000 kcal of energy, who much energy will be available to the owl?
Answer:
Generally, consumers only receive 10% of the energy from what they eat. So, if the grass had 220,000 kcal of energy, then the cow would receive 10% of that - 200kcal. And then when a human eats the cow, it will only receive 10% of the cow's energy. This is because within a food chain, energy is lost as organisms use their energy to survive - like moving and producing heat (if endothermic). So consumers do not get 100% of their food's energy. Hope this helps a little.
Explanation:
When carbon is completely combusted in the presence of oxygen the only product produced is carbon dioxide as shown in the following equation, C+O2——>CO2 If 12 grams of carbon are burned, how many grams of carbon dioxide will be produced?
Answer:
C.44g is that one okkkkkkkkkkkkkkkk
if it were a very hot day , how would the speed at which we smelled the perfume change ? what about a very cold day ? why ?
Explanation:
On a hot day, the speed at which we perceived the smell of the perfume will be much faster due to the increase in kinetic energy of the perfume molecules.
Based on the kinetic molecular theory of gases, the average motion of particles increases as their thermal energy increases. On a hot day, the heat causes an increase in the average kinetic energy of the particles and the perfume molecules moves faster.
On a cold day, the molecules are slower and the rate at which we perceive the perfume smell is very slow. The particles will diffuse less faster and this is due to the low average kinetic energy they possess.
How many moles are in 4.81x10^24 atoms of boron(B) ?
Show all of your work. Include units. round your answer to the correct number of significant figures.
Answer:
7.99 moles of boron
Explanation:
Given data:
Number of moles of B = ?
Number of atoms of B = 4.81 × 10²⁴ atom
Solution:
Avogadro number:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance. The number 6.022 × 10²³ is called Avogadro number.
1 mole = 6.022 × 10²³ atoms
4.81 × 10²⁴ atom × 1 mol / 6.022 × 10²³ atoms
0.799 × 10¹ mol
7.99 moles
Three quantum numbers are derived from Schrodinger’s equation that describe the probability of finding an electron around a nucleus: the principal quantum number, the angular momentum quantum number, and the magnetic quantum number. Explain each quantum number, including associated shapes, numbers, letters and values.
(please help)
Answer:
Principal Quantum Number (n) = energy level (1s2)
Angular Momentum Quantum Number (l) = sub-shell (1s2)
Magnetic Quantum Number (mi) = specific orbital electron occupies
range of (n) = 1-7
range of (I) = s, p, d , f
Explanation:
Answer:
Principal Quantum Number: designates the principal electron shell. Angular Momentum Quantum Number-This quantum number determines it's shape of an orbital and thus it's angular distribution. This quantum number determines the number of orbital numbers, their orientation within the sub-shell.
Principal Quantum Number, n
It describes the size of its orbital and of the main energy level. It is represented by n. Where, n = 1,2,3,4....stands for K, L, M, N shell and so on..
ngular Momentum Quantum Number l
It describes the shape of the orbital and thus the angular distribution. It can take from 0 to (n - 1). That is l = 0,1,2,...,(n - 1)
The magnetic Quantum Number, m
It describes the orientation of the orbitals. It is represented as . The value of this quantum number ranges from . When l = 2, the value of will be -2, -1, 0, +1, +2.
Explanation:
Calculate Ratios In the following reaction, how many molecules of HCI are needed to produce four molecules of H20? 2HCl(aq) + Ca(OH)2(aq) +CaCl2(aq) + 2H20(1)
Answer:
Explanation:
Mole ratios are used as conversion factors between products and reactants in stoichiometry calculations.. For example, in the reaction . 2H₂(g) + O₂(g) → 2H₂O(g) The mole ratio between O₂ and H₂O is #(1 mol O₂)/(2 mol H₂O)#.
To calculate the atoms of an element in a given molecule, we need to multiply stoichiometry by the number that is written on the foot of that element. The mole ratio between HCl and H20 is 1:1.
What is Balanced equation?Balanced equation is the one in which the total number of atoms of a species on reactant side is equal to the total number of atoms on product side. The mass of the overall reaction should be conserved. There are so many types of chemical reaction reaction like combination reaction, displacement reaction.
Physical state should be written in brackets. s means solid, l means liquid, g means gas. Mole ratios are used as conversion factors between products and reactants in stoichiometry calculations. The mole ratio between HCl and H20 is 1:1.
Therefore, the correct option is option A.
Learn more about the balanced equation, here:
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two examples for magnetic and nonmagnetic materials
Answer:
Magnetic: Iron and nickel
Nonmagnetic: Rubber, feathers and/or leather
Explanation:
Hope this helps!
4. What gives blood its red color?
a. hemoglobin
O
b. red blood cells
O
c. platelets
d. plasma
Answer:
the best answer would be A
Explanation:
cause it contains a red colored compound.
Which of the following elements has the highest atomic radius, Sr or Cu
Answer:
Sr or Strontium
Explanation:
sr: strontium has atomic radius of 255pm
cu: copper has an atomic radius of 128pm
they teach you in chem how to do it based off the chart but I don't remember that method
Which of these elements could gain one electron to form an ionic bond with potassium explain why
Answer:
ChlorineIt has 7 electrons in it last shell. it will gain one electron to complete its octet and become Cl-. The ionic bond of chlorine form with potassium is Kcl ( potassium chloride)
Phosphorus has 5 electrons in its last shell it need 3 more electron to stable .Sulphur has 6 electron. it needs 2 electrons Argon is already stable as it has 8 electrons in its last shell it will not gain or loose any electronsTo solve such this we must know the concept of ionic reaction. Cl is the element could gain one electron to form an ionic bond with potassium.
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.
Potassium will act as cation as K⁺, chlorine has 7 electrons in it last shell, it can gain one electron to complete its octet and become Cl⁻. The ionic compound of Cl with K is KCl.
Phosphorus has 5 electrons in its last shell it so, it needs 3 more electron to get stable .Sulphur has 6 electron, it needs 2 electrons to get stable. Argon is already stable as it has 8 electrons in its last shell so, it will not gain or loose any electrons.
Therefore, Cl is the element could gain one electron to form an ionic bond with potassium.
Learn more about the chemical reactions, here:
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1. True or false, phosphorus-33 is an isotope
Explanation:
it's answer is false
hope it helps you
22
Silicon(IV) oxide is a covalently bonded compound.
Which statements are correct?
1
2
Silicon atoms form four single bonds in silicon(IV) oxide.
Oxygen atoms form two double bonds in silicon(IV) oxide.
Silicon(IV) oxide has a high melting point.
Silicon(IV) oxide contains one silicon atom and four oxygen atoms.
3
4
с
D
2 and 3 only
3 and 4 only
B
1 and 3 only
1 and 2 only
А
А
Answer:
2 and 3 only
Explanation:
The formular for the compound; Silicon(IV)oxide is SO2
1. Silicon atoms form four single bonds in silicon(IV) oxide.
This statement is wrong because the silicon is doubly bonded to two oxygen atoms.
2. Oxygen atoms form two double bonds in silicon(IV) oxide.
This statement is correct.
3. Silicon(IV) oxide has a high melting point.
This statement is correct Due to it's macromolecular structure, it is able to form thousands of covalent bonds between it's sulphur and oxygen sub units.
4. Silicon(IV) oxide contains one silicon atom and four oxygen atoms.
This statement is wrong as silicon(iv) oxide contains only two oxygen atoms.
Explain why heating a liquid causes it to evaporate more quickly.
Answer:
If a liquid is heated the particles are given more energy and move faster and faster expanding the liquid. The most energetic particles at the surface escape from the surface of the liquid as a vapour as it gets warmer. Liquids evaporate faster as they heat up and more particles have enough energy to break away.
Explanation:
What is responsible for the blue sky?
Answer:
sun shine
Explanation:
Sunlight reaches Earth's atmosphere and is scattered in all directions by all the gases and particles in the air. Blue light is scattered more than the other colors because it travels as shorter, smaller waves. This is why we see a blue sky most of the time
Answer:
Sunlight
Explanation:
Sunlight reaches Earth's atmosphere and is scattered in all directions by all the gases and particles in the air. Blue light is scattered more than the other colors because it travels as shorter, smaller waves. This is why we see a blue sky most of the time. Blue light is scattered in all directions by the tiny molecules of air in Earth's atmosphere. Blue is scattered more than other colors because it travels as shorter, smaller waves. This is why we see a blue sky most of the time. ... Also, the surface of Earth has reflected and scattered the light.
