Answer:
E = 3.035× 10-¹⁹J = 1.9eV
f = 4.58 × 10¹⁴Hz
Explanation:
wavelength = 6.55 × 10-⁷m
c = 3 × 10⁸m/s
f = ?
E = ?
a) f = c/wavelength
f = 3 × 10⁸/6.55 × 10-⁷
f = 4.58 × 10¹⁴Hz
b) E = hc/wavelength
E = 6.626×10-³⁴ × 3 × 10⁸/ 6.55 × 10-⁷
E = 3.035 × 10-¹⁹J
1ev = 1.6 × 10-¹⁹J
Therefore E = 3.035/1.6 = 1.9eV
Hope it's not too late man
What is the final temperature when 625 grams of water at 75.0° C loses 7.96 x 104 J?
The specific heat of water is 4.18 J/gCº.
Answer: A copper cylinder has a mass of 76.8 g and a specific heat of 0.092 cal/g·C. It ... J ql = mwcwΔTw. ΔTw = ql/(m x c). ΔTw = 7.96 x 10. 4. J/(625 g x 4.18 J/g·K) = 30.5 ...
Explanation:
How many valence electrons would be shown in the electron dot diagram of a helium atom?
Answer:2
Explanation:
The number of valence electrons for a helium atom is 2. This can be confirmed by looking at the electronic configuration.
Helium atom:Helium is placed in the noble gas series as it has certain properties of it. The atomic number of helium is 2. Thus, it has two electrons in its outermost shell but it has completely filled orbital.
Electronic configuration of He = 1s2
Thus, for drawing the electron dot structure, there are two valence electrons.
Find more information about Helium atom here:
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Match the definitions on the left with the terms on the right.
Answer:what defino? I don’t see nun
Explanation:
Answer:
answer in picture
Explanation:
what is the main material that make up the tusk of an elephant
Answer:
Ivory
Explanation:
The outside of the tusk is made of ivory, but 2/3 of the tusk is their head, made of tissue. But I think the answers Ivory. Thats the reason why poachers go for the tusks. Because humans like ivory :/
Which chemical equation below is balanced to correctly represent the Law of Conservation of Mass?
Answer:
The 3rd equation.
Cl2 + 2NaBr —> 2NaCl + Br2
Explanation:
The law of conservation of matter (mass) states that matter can neither be created nor destroyed during a chemical reaction but can be transferred from one form to another. This implies that unbalanced chemical equation shows that matter (mass) has been created or destroyed.
Now, we shall determine which equation is balanced as follow:
1. 2Cl2 + NaBr —> 2NaCl + Br2
Reactant >>>>>>>> Product
4 Cl >>>>>>>>>>>> 2 Cl
1 Na >>>>>>>>>>>> 2 Na
1 Br >>>>>>>>>>>> 2 Br
Thus, the equation is not balanced.
2. Cl2 + NaBr —> NaCl + Br2
Reactant >>>>>>>> Product
2 Cl >>>>>>>>>>>> 1 Cl
1 Na >>>>>>>>>>>> 1 Na
1 Br >>>>>>>>>>>> 2 Br
Thus, the equation is not balanced.
3. Cl2 + 2NaBr —> 2NaCl + Br2
Reactant >>>>>>>> Product
2 Cl >>>>>>>>>>>> 2 Cl
2 Na >>>>>>>>>>> 2 Na
2 Br >>>>>>>>>>>> 2 Br
Thus, the equation is balanced.
From the illustration made above only the 3rd equation is balanced. And this is in line with the law of the Conservation of matter (mass) as matter (mass) was not created nor destroyed during the chemical reaction but was transferred to other forms.
A chef fills a 60-ml container with 45.3 g of cooking oil. What is the density of the oil?
Answer:
0.76 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
From the question we have
[tex]density = \frac{45.3}{60} \\ = 0.755[/tex]
We have the final answer as
0.76 g/mLHope this helps you
Which of these is an example of physical change
A) iron melting
B) steel rusting
C) paper burning
D) wood decaying
Answer:
it is A mark me big brain pls
Explanation:
What is chemical potential energy?
A. Energy stored by atoms
B. Energy stored in height differences
C. Energy from gravity
D. Energy of motion
Answer:
A
Explanation:
please pick me for brainliest
Answer:
D
Explanation:
All about the motion.
The large holes that can form in Limestone eventually lead to the formation of caves and caverns.
True or False?
Which of the following statements is true?
A. Cations are always larger than the atoms from which they form.
B. Cations are always the same size as the atoms from which they form.
C. Anions are always larger than the atoms from which they form.
D. Anions are always smaller than the atoms from which they form.
Answer:
B. Cations are always the same size as the atoms from which they form.
Explanation:
That's i read in the book
"Anions are larger in size than the atoms from which they form" is a true statement. Therefore, option (C) is correct.
What are anions and cations?A cation contains more protons than electrons in it, which give it a net positive charge. A cation can be formed by losing one or more electrons must be lost by atoms.
The charge on the ion will be equal to the number of electrons lost as indicated after the chemical symbol. For example, silver (Ag) has lost one electron to become Ag⁺. The size of the cation is always smaller than the atom from which it formed.
An anion contains more electrons than protons which gives it a net negative charge. An anion can be formed by gaining one or more electrons or typically pulled away from other atoms.
The charge of the anion will be equal to the number of electrons gained, which is indicated after the chemical symbol. For example, chlorine (Cl) accepts one electron to become Cl⁻.
The size of an anion is greater than the atoms from which it formed as the number of electrons in the ion increases and effective nuclear charge decreases.
Learn more about anions and cations, here:
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A science teacher placed a magnesium wire in flame.the wire turned white where the flame touched it. which statement best explains the chemical change
A. a new substance formed
D. the magnesium wire changed shape
the subject is science
Answer:
A
Explanation:
The correct answer would be that a new substance is formed.
When magnesium wire is burnt in the presence of oxygen, the wire reacts with oxygen and a new substance known as magnesium oxide is formed. The new substance is usually white in color and the equation of the reaction is as below:
[tex]2 Mg (s) + O_2 (g) --> 2 MgO (s)[/tex] (white)
Hence, the correct option is A.
Answer:
Explanation:A new substance formed. Promise.
The diagram shows changes of state between solid, liquid, and gas. The atoms of a substance lose energy during a change of state. Before the change, the atoms are close together but are able to slide past one another.Which arrow represents the change of state described above?
M
N
P
Q
Answer:
D. P
Hope it works!
Explanation:
Any 1 help with Chemistry here??
how does carbon dioxide get into the atmosphere?
Answer:
By condensation.
Explanation:
Have a nice day dear
Which gas contains the same number of molecules as 9g of water?
A) 2g of hydrogen
B) 14g of nitrogen
C) 32g of oxygen
D) 44g of carbon dioxide
Answer:
B) 14g of nitrogen
Explanation:
To calculate number of molecules in 9g of water, we first convert mass to mole by using mole = mass/molar mass i.e.
mole = 9g/18g/mol of water
mole = 0.5mol
Next, we multiply by 6.022 × 10^23 molecules to get 3.011 × 10^23 molecules in 9g of water (H2O).
- For hydrogen gas: Molar Mass = 2g/mol, mass = 2g
mole = 2/2 = 1
No. of molecules = 1 × 6.022 × 10^23 = 6.022 × 10^23 molecules.
- For Nitrogen gas: Molar Mass = 28g/mol, mass = 14g
mole = 14/28 = 0.5mol
No. of molecules = 0.5 × 6.022 × 10^23 = 3.011 × 10^23 molecules.
- For Oxygen gas: Molar Mass = 32g/mol, mass = 32g
mole = 32/32 = 1mol
No. of molecules = 1 × 6.022 × 10^23 = 6.022 × 10^23 molecules.
- For carbondioxide gas: Molar Mass = 44g/mol, mass = 44g
mole = 44/44 = 1mol
No. of molecules = 1 × 6.022 × 10^23 = 6.022 × 10^23 molecules.
Based on he results of each calculation, NITROGEN contains the same number of molecules as 9g of water
Express in scientific notation. Choose the answer with the proper number of significant figures.
9x109
4.5 x 10
Answer:
4.5 times 10 = 45
Explanation:
"Non-zero digits are always significant. Any zeros between two significant digits are significant. A final zero or trailing zeros in the decimal portion ONLY are significant."
SIMPLE ANSWERS ONLY I ALREADY GOOGLED AND DIDN'T FIND ANYTHING PLEASE ANSWER IN YOUR OWN WORDS.
How is atomic mass calculated for elements on the periodic table.
Explanation:
The atomic mass of elements on the periodic table are derived from the proportion of the geonormal abundance of the different isotopes of an element.
Using a mass spectrometer, the proportion/percentage/fraction by which each of the isotopes of an element occurs in nature is determined. This proportion is the geonormal abundance. From this the atomic mass of the element can be derived. Simply multiply the mass by the abundance and sum the values for the same isotopes together.HELPPPP!!! I NEED IT VERY MUCHHHH
Answer:
mabye C at least if its not right sorry .
IMMA WAIT FOR MY BABY EVEN IF IT TAKES ALL NIGHT !!!!!!
Answer:
um okay lol
Explanation:
Answer:
Oh ok
Explanation:
Also can u pls mark me brainliest im new pls
2. If 300.0 mL of a 2.5 M solution of nitric acid is added to 500.0 mL of water, what is the molarity of the
dilute solution?
Answer:To calculate the Molarity of a 70 wt. % Nitric Acid the number of moles of HNO 3 present in 1 liter of acid needs to be calculated. Knowing the density of the acid to be 1.413 g/mL, we can calculate the weight of 1 L of 70% HNO 3 to be 1413
Explanation:
which of the following is not the same as 0.032 liters?
a)32 mL
b)0.00032 hL
c)320 cL
The composition of a compound is 6.27 g calcium and 1.46 g nitrogen.
Calculate the empirical formula.
Answer:
Ca₃N₂
Explanation:
The empirical formula is the simplest whole-number ratio between moles of each element present in a molecule.
Thus, we need to convert mass of each atom to moles and find the ratio between these as follows:
Moles N:
1.46g * (1mol / 14.0067g) = 0.104moles
Moles Ca:
6.27g * (1mol / 40.078g) = 0.156moles
The ratio between Moles N and moles of Ca is:
0.156moles / 0.104 moles = 1.5
That means there are 1.5 moles of Ca per mole of N. As empirical formula must be given in whole numbers:
There are 3 moles of Ca per 2 moles of N.
Empirical formula is:
Ca₃N₂BEBE
Use the activity series below to predict whether the following reactions will take place.
803
F2 > Cl2 > Br2 > 12
Cl2 + 2Rbl - 2RbCI+ 12
12 + NiBr2 - Nil2 + Brz
yes
yes
no
0
no
Reaction 1 : yes
Reaction 2 : no
Further explanationThe metal activity series is expressed in voltaic series
Li-K-Ba-Ca-Na-Mg-Al-Mn- (H2O) -Zn-Cr-Fe-Cd-Co-Ni-Sn-Pb- (H) -Cu-Hg-Ag-Pt-Au
The more to the left, the metal is more reactive (easily release electrons) and the stronger reducing agent
The more to the right, the metal is less reactive (harder to release electrons) and the stronger oxidizing agent
So that the metal located on the left can push the metal on the right in the redox reaction
From activity series of Halogen :
F₂>Cl₂>Br₂>I₂
F₂ is the strongest oxidizing agent
1. Reaction
Cl₂ + 2Rbl - 2RbCI+ I₂
Cl₂>I₂⇒reaction can occur⇒yes, reactions will take place.
2. Reaction
I₂ + NiBr₂ - NI₂ + Br₂
Br₂>I₂⇒Reaction can't occur⇒no, reaction will not take place
state the volume of SO2 and O2 at RTP that would produce 180cm3 of SO3
Answer:
(180 cm^3 SO3) x (2 mol SO2 / 2 mol SO3) = 180 cm^3 SO2
(180 cm^3 SO3) x (1 mol O2 / 2 mol SO3) = 90 cm^3 O2
Which of the following are chemical or nuclear reactions?
1. chemical plant explosion
2. Tsar Bomba
3. meteor strike
4. Tunguska Event
5. Super Volcano eruption
6. fusion powering the sun
Answer:5) super Volcano eruption
Explanation:
Answer:
#1, #2, #4, and #6 are the answers.
Explanation:
#2, #4, and #6 have something to do with radioactivity which is mostly categorized in nuclear reactions, #3 and #5 are partly categorized in thermal reactions while a chemical plant explosion is almost categorized as a chemical bomb; Chemical explosions may be either decomposition or combination reactions. Decomposition reactions occur in materials such as trinitrotoluene (TNT) and nitroglycerine. Combination reactions require that two or more components react together exothermically to produce hot gases. Some examples are ammonium nitrate and fuel oil (ANFO), and gunpowder (potassium nitrate, carbon, and sulfur). In conclusion, #1, #2, #4 and #6 are the answers.
I don’t really have a question... and my teacher says I need to give one related to this reading above :/
Can somebody plz give one that makes sense (WILL MARK BRAINLIEST)
Answer:
Just say I wonder why teachers give homework :/
Explanation:
How many molecules are in 32 grams of NH3?
Answer:
1.87897962011728
Explanation:
What type of relationship exists between
dissociation constant and pk values
A Linear
B Directly Proportional
C Direct
D Inverse
Answer: D inverse . The product of Ka and Kb equals the auto-dissociation constant for water.
Explanation: i hoped that helped and Plz give as a brainliest !!
can someone solve c and d?
Answer:
Na + + e - → Na.
Pb 2+ + 2e - → Pb.
2H + + 2e - → H 2
Explanation:
In the redox reaction AgNO3 + Na → NaNO3 + Ag, which element has been
oxidized?
Answer:
sodium I think .............