Answer:
I'm not going to give you notes but I'm going to give you a tip for notes take what you think is the most important thing about the text and basically paraphrase it into your own words if that helps
Which part of the immune system can be "trained" using vaccines?
Calculate the energies of the n=2 and n=3 states of the hydrogen atom in Joules per
atom
Answer:
See Explanation
Explanation:
Positional Energy for electron as function of principle energy level (n)
=> Eₙ = -A/n²; A = 2.18x10⁻¹⁸J
Positional Energy for electron in n=2 => E₂ = -2.18x10⁻¹⁸/(2)² = -5.45x10⁻¹⁹J
Positional Energy for electron in n=3 => E₃ = -2.18x10⁻¹⁸/(3)² = -2.42x10⁻¹⁹J
ΔE(n=3→2) = -5.45x10⁻¹⁹J - (-2.42x10⁻¹⁹J) = -3.03x10⁻¹⁹J
Help me with this . I'm bad at chemistry . I’ll give you a brain list . Don’t answer if u don’t know at all .
Answer:
2.
a.Sodium bromide
b. Magnesium dichloride
c. Lithium iodide
not sure about 3 or 4 sry
name the group and period of an element having atomic number 21
Answer:
The element in question here is Scandium, with an atomic number of 21. It is situated in Group 3 and Period 4 of the Periodic Table.
Explanation:
Hope this helped!
What is immigration and emigration
Answer:
well for me I think
Explanation:
immigration is the movement which involves an individual moving from a present place to another environment
That is going out
WHILE
Emigration is the process where a person comes into a particular environment
That means coming in
True or False: Most metals are found to occur naturally in their uncombined states.
Answer:
I think it's true. But I'm not sure
Answer:
True
Explanation:
What type of reaction occurs between an element and a compound?
Answer:
exothermic reaction
Explanation:
because it occurs in the presence of heat
Will give brainliest
Answer:
C
Explanation:
The concept behind, is mole ratio of Al:FeO
Balance this equation.
_Mg +_Cl2 -->_MgCl2
Answer:
1Mg + 1Cl2 = 1MgCl2
Explanation:
Hi! When balancing an equation, you want to make sure that there are equal amounts of each element on both sides. When looking at the equation that you provided in the question, look and count how many of each element are on each side. I can see that there is 1 Mg ion on the left and 1 Mg ion on the right. There are also 2 Cl ions on the left and 2 Cl ions on the right. Because they are already equal, the coefficients in front of each compound will be 1. If the amounts were different on each side, that is when you would need to add different coefficients.
Hope this helps! Let me know if you have any other questions about this!
15
Question 56 (1 point)
What is the name of the compound with the chemical formula SnSnO3?
Answer: sodium sulfite
Explanation:
Explain how atomic
radius, valence electrons
and effect nuclear charge
creates the trend for metal
reactivity.
Answer:A higher effective nuclear charge causes greater attractions to the electrons, pulling the electron cloud closer to the nucleus which results in a smaller atomic radius. Down a group, the number of energy levels (n) increases, so there is a greater distance between the nucleus and the outermost orbital.
Answer:
A higher effective nuclear charge causes greater attractions to the electrons, pulling the electron cloud closer to the nucleus which results in a smaller atomic radius. Down a group, the number of energy levels increases, so there is a greater distance between the nucleus and the outermost orbital.Explanation:
d = 7 V = 950 cm M = 95 g
0.1 g/cm3
0.1 cm3
90,250 g
90,250 g/cm3
Answer:
daddy chill
Explanation:
you weigh out 43.9 g of potassium (K). How many moles of potassium did you weigh? How many atoms?
Answer:
1.12 moles of potassium
6.76x10²³ atoms of potassium
Explanation:
In order to convert g of potassium to moles, we need to use its molar mass (which we can find via the periodic table):
Molar Mass of K = 39.09 g/mol43.9 g K ÷ 39.09 g/mol = 1.12 mol KThen, to convert moles into atoms, we use Avogadro's number (6.023x10²³ atoms per mole):
1.12 mol K * 6.023x10²³[tex]\frac{atoms}{mol}[/tex] = 6.76x10²³ K atoms
The percent ionization of a 0.350 M HC,H,O2 solution. Ka(HC2H302)
Answer:
The answer is 56
Explanation:
i need points
Which event would most likely lead to a thunderstorm g i v i n g b r a i n l e s i t HELP
--
Answer:
A
Explanation:
hope it helps
Answer:
A
Explanation:
I got right
What happens to molecular energy(heat) in water when water vapor becomes a liquid?
Group of answer choices
Water vapor gives up heat energy.
Water vapor absorbs heat energy.
As water's mass increases it absorbs energy.
Water vapor retains the same heat energy.
Answer:
Water vapor retains the same heat energy.
Answer:
water vapor gives up heat energy.
Explanation:
Took a quiz and got it right
A paint chip is placed in ethanol and curls what type of paint is it
Answer:
it is probably acrylic or latex
Explanation:
There are two types of chemical compound one is covalent compound and other is ionic compound, covalent compound formed by sharing of electron and ionic compound formed by complete transfer of electron. Therefore, the type of paint is acrylic or latex.
What is chemical Compound?Chemical Compound is a combination of molecule, Molecule forms by combination of element and element forms by combination of atoms in fixed proportion.
An ionic compound is a metal and nonmetal combined compound. Ionic compound are very hard. They have high melting and boiling point because of strong ion bond. If the chip remains flat when put in ethanol, it is probably an oil-based paint. If the chip curls, it is probably acrylic or latex. So, The type of paint is acrylic or latex.
Therefore, the type of paint is acrylic or latex.
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PLEASEEE HELP ?!?!?!
which of the following processes provide evidence of the particulate nature of matter
I. Diffusion
II. Filtration
III. Osmosis
A. I and II only
B. I and III only
C. II and III only
D. I, II and III
Answer:
B
Explanation:
I think the answer is Diffusion and Osmosis
The processes that provide evidence of the particulate nature of matter would be diffusion and osmosis.
Matter is defined as anything with mass/weight and able to occupy space. Matters could be molecules of solid, liquid, or gases. The molecules of each category of matter have their specific characteristics.Molecules of liquids and gases are able to diffuse. Diffusion is defined as the movement of molecules from the region of high concentration to the region of low concentration. Molecules of solids in the dissolved form are also able to diffuse. Water molecules are also able to move from the region of high to the region of low water potentials by osmosis in the presence of a semi-permeable membrane.Thus, both diffusion and osmosis back up the particulate nature of matter.
More on the particulate nature of matter can be found here: https://brainly.com/question/15230454?referrer=searchResults
What is the name of the compound with the formula LiNO3?
Answer:
Lithium nitrate
Explanation:
Lithium nitrate is an inorganic compound with the formula LiNO3. It is the lithium salt of nitric acid (an alkali metal nitrate).
An elemental metal contains how many types of atoms?
a. 1
b. 2
c. 3
d. 4
Answer:
a
Explanation:
all elemental metals are made up of only one type of element
Answer:
It is 1.
Explanation:
An ideal gas sample is confined to 3.0 L and kept at 27 °C. If the temperature is raised to 77 °C and the initial pressure was 1500 mmHg, what is the final pressure?
The gas is confined in 3.0 L container ( rigid container) ⇒ the volume remains constant when the temperature is increased from from 27oC to 77oC and therefore V1=V2 .
Hope it helps you please mark as brainlistIdeal gas law is valid only for ideal gas not for vanderwaal gas. Ideal gas is a hypothetical gas. Vanderwaal gas can behave as ideal gas at low pressure and high temperature. Therefore the final pressure is 1,750 mmHg.
What is ideal gas equation?Ideal gas equation is the mathematical expression that relates pressure volume and temperature.
Mathematically the relation between Pressure, volume and temperature can be given as
PV=nRT
where,
P = pressure of gas
V= volume of gas
n =number of moles of gas
T =temperature of gas
R = Gas constant = 0.0821 L.atm/K.mol
At constant volume, the above equation can be rearranged as
P₁/T₁ = P₂/T₂
Substituting all the given values in the above equation, we get
1500 ÷300= P₂÷350
P₂ =1,750 mmHg
Therefore the final pressure is 1,750 mmHg.
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How many atoms are in a sample containing 4.000 moles of carbon?
A)6.022 x 10
23
atoms
B)2.408 x 10
24
atoms
O
24
C)7.233 x 10 atoms
D)2.893 x 10
25
atoms
Answer:
c I think but that's only what i think
Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 24.088×10²³ atoms of carbon are in sample containing 4.000 moles of carbon. The correct option is option B.
What is mole?The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity or amount of substance. We know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number.
Mathematically,
number of atoms/molecules/ formula units of carbon= number of moles of carbon × 6.022×10²³
number of moles of carbon= 4 moles
substituting all the given values in the above equation, we get
number of atoms/molecules/ formula units of carbon= 4 × 6.022×10²³
number of atoms/molecules/ formula units of carbon=2.4088×10²⁴ atoms of carbon
There are 2.4088×10²⁴ atoms of carbon
Therefore, 24.088×10²³ atoms of carbon are in sample containing 4.000 moles of carbon. The correct option is option B.
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Describe the reaction of zinc with sulphuric acid
Answer:
Zinc reacts with dilute sulphuric acid to produce hydrogen gas (H2) and zinc sulphate. This is an example of displacement reaction of a non-metal by a metal. ... ZnSO4 is different in chemical composition and chemical properties than Zn and H2SO4 so it is a chemical change.
Answer:
Reaction of Zinc with Dilute Sulphuric Acid
Zinc is more reactive than hydrogen and it displaces hydrogen from dilute acids. Zinc reacts with dilute sulphuric acid to form zinc sulphate and hydrogen gas is evolved. This is a single displacement reaction of a non-metal by a metal. ... So, this reaction is a chemical change.
Law of Universal Gravitation (what factors affect gravity and how?)
Explanation:
Hey there!
According to the law of gravitation, the factors that affects the gravity are:
Mass of the heavenly bodies.Distance from the centre of the body to next body.Mass of heavenly bodies:The mass of heavenly bodies affect the gravity. We know that gravity is directly proportional to the mass of heavenly bodies. so, when the mass is more there is more gravity and where there is less mass there is less gravity.
Distance from the centre of the body to next body: It is one of the factor to influence gravity. When there is more distance there is less gravity and where there is distance more force is there. Is means gravity is inversely proportional to the distance between the bodies.
Hope it helps...
Which is a pure substance?
They are chemically bonded together.
They can be classified as pure substances.
They have fixed ratios between their components.
They can be separated by physical processes.
Answer: C. They have fixed ratios between their components.
How can the rate of a reaction be increased?
(A) decreasing the amount of reactants
(B) having more surface area
(C) diluting a solution
(D) lowering the temperature
Explanation:
Rate of reaction can be increased by having more surface area.
Therefore,
Option B is correct✔
Answer:
b
Explanation:
Which of the following would be most useful in trying to obtain procedural information to replicate an experiment previously published?
Answer: Peer-reviewed journal article is the most useful because the information in them had been carefully scrutinized and aproved by people who are experts in that particular field.
How does adding a lone pair affect the position of existing atoms and lone pairs
Answer:
How does adding a lone pair affect the position of existing atoms and lone pairs? It decreases the angles between the atoms - the atoms are moving closer because they are being repelled further away from the lone pairs then they are from the other atoms
Explanation:
hope it helps!
How many protons, neutrons, and electrons does 35/17 Cl ^ 1- have?
Answer:
In accordance to the pic
The number of protons in Cl-35 is 17 and the number of neutrons is 18. The number of Cl is 17 whereas the chloride ion Cl⁻ have 18 electrons.
What is chlorine?Chlorine is 17th element in periodic table. Cl is includes in the 17th group of p -block. Cl contains 7 valence electrons and it needs one more electron to attain complete configuration. It is highly electronegative and will easily gain an electron to achieve octet.
Atoms in neutral state have equal number of electrons and protons and this number is equal to the atomic number. The mass number is the sum of number of protins and neutrons.
The atomic number of Cl is 17. Hence the number of protons is 17 and the mass number is 35. So that number of neutrons is 35 - 7 =18. When Cl gains an electron it forms the anion Cl⁻. Hence, the number of electrons in Cl⁻ is 18.
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middle school science help please
Answer:
The answer is 'All of the above'
Explanation:
because the hydrogen ions are represented by the symbol H+, they increase the PH value of a solution if less amount is added but they decrease the PH value of a solution if a larger amount of hydrogen ions are added but still they increase the PH value, and of course, they contribute to a solution by a base.
Answer:
Hydrogen ions are represented by H+.
Explanation:
Hydrogen ions usually decreases the pH value when added to a solution.Hydrogen ions are contributed to a solution by a acid.