1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
lisabon 2012 [21]
3 years ago
5

The moon is not visible during which phase

Chemistry
2 answers:
vaieri [72.5K]3 years ago
5 0

I believe the answer is B. new moon

Tanzania [10]3 years ago
4 0
The answer would be B. New Moon.
You might be interested in
In the lab you measure a clean dry crucible and cover to be 24.36 grams. You obtain a 2cm piece of pure magnesium metal. After s
mart [117]

Answer:

1) 0.3g Mg

2)0.5g MgO

3)0.2g O

4)0.01mol Mg & 0.01mol O

5)0.01mol MgO

6) Empirical formula MgO

Explanation:

The mass og Mg is obtained by substracting 24.36g from 24.66g:

24.66 - 24.36 = 0.3g Mg

The ignition of Mg means that it's reacting with oxygen to form an oxide. The increase in the crucible mass after the Mg ignition is due to the addition of oxygen. However, the addition of few drops of water produces a new compound: a hydroxide. According to the oxidation state og Mg (2+), the only magnesium oxide possible is MgO. It happens because the oxidation state of oxygen in oxides is 2-. Which means that just one oxygen atom is required to electrically neutralize one magnesium atom.

We can use a conversion factor to know how much MgO is made from from 0.3 g of Mg:

0.3g Mg*\frac{16gO}{24.3gMg}= 0.2g O

Thereby the mass of the oxide is 0.2g O + 0.3g Mg = 0.5g MgO

We convert the mass of oxygen and magnesium to the respective amounts in moles by using conversion factors:

0.2g O*\frac{1 mol O}{16g O}= 0.01mol O

0.3g Mg*\frac{1mol Mg}{24.3g Mg}= 0.01mol Mg

The moles of MgO can be obtained from:

0.5g MgO*\frac{1mol MgO}{40.3g MgO}= 0.01mol MgO

To obtain the empirical formula, the amount fo moles of each elements must be divided by the smallest one, in this case, 0.01.

The result for both number of  Mg atoms and O atoms is 1. This can be interpreted to mean that there is a Mg atom for each O atom forming the  formula unit of the compound.

The step when water is added to the compound resulting after heating does not affect the calculations necessary for the magnesium oxide.

4 0
3 years ago
Can someone please try and help me with this? I'll give brainliest if I can
sineoko [7]

Answer:

boom Corvette Corvette pop in the popular vet like that like that why you walk like that why you talk like that like I said boom boom boom I'm in the cold Mira, she needs to be back I remember seeing everyone Nee u i

6 0
2 years ago
what is the molarity of a solution made by dissolving 18.5 grams of NaCL into enough water to reach 450.0ML​
ValentinkaMS [17]

Answer:

0.702M

Explanation:

Molarity of a solution, which refers to the molar concentration of that solution can be calculated thus;

Molarity = number of moles (n) ÷ volume (V)

Firstly, we convert 18.5 grams of NaCl to moles using the formula; mole = mass/molar mass

molar mass of NaCl = 23 + 35.5 = 58.5g/mol

mole = 18.5/58.5

mole = 0.32moles

Volume of water (V) = 450mL = 450/1000 = 0.450L

Molarity = n/V

Molarity = 0.32/0.450

Molarity = 0.702M

4 0
3 years ago
The work function of an element is the energy required to remove an electron from the surface of the solid element. The work fun
ANEK [815]

Answer:

\lambda=428.04\ nm

Explanation:

The work function of the lithium = 279.7 KJ/mol  (Source)

It means that  

1 mole of electrons can be removed by applying of 279.7 kJ of energy.

Also,  

1 mole = 6.023\times 10^{23}\ electrons

So,  

6.023\times 10^{23} electrons can be removed by applying of 279.7 kJ of energy.

1 electron can be removed by applying of \frac {279.7}{6.023\times 10^{23}}\ kJ of energy.

Energy required = 46.44\times 10^{-23}\ kJ

Also,  

1 kJ = 1000 J

So,  

Energy required = 46.44\times 10^{-20}\ J

Also, E=\frac {h\times c}{\lambda}

Where,  

h is Plank's constant having value 6.626\times 10^{-34}\ Js

c is the speed of light having value 3\times 10^8\ m/s

So,  

46.44\times 10^{-20}=\frac {6.626\times 10^{-34}\times 3\times 10^8}{\lambda}

\lambda=\frac{6.626\times 10^{-34}\times 3\times 10^8}{46.44\times 10^{-20}}

\lambda=\frac{10^{-26}\times \:19.878}{10^{-20}\times \:46.44}

\lambda=\frac{19.878}{10^6\times \:46.44}

\lambda=4.2804\times 10^{-7}\ m

Also,  

1 m = 10⁻⁹ nm

So,  

\lambda=428.04\ nm

4 0
3 years ago
What is the element that has the ending configuration of 4d^4​
Maru [420]

Answer:

Molybdenum

Explanation:

Molybdenum is a chemical element with the symbol Mo and an atomic number of 42. This implies a total of 42 electrons in its orbital.

The atomic weight of  Mo is 95.94g/mol.

Using the sublevel notation system, the electrons can be filled into the orbitals as shown below:

                      1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d⁴

        The ending configuration of this element is therefore 4d⁴

7 0
3 years ago
Other questions:
  • A gram of gold has the same ____ as a kilogram of gold
    14·1 answer
  • A solution of ammonia has a pH of 11.8. What is the concentration of OH– ions in the solution?
    14·2 answers
  • Is ineffective collision's the answer? Please correct me if not, thank you. :)
    14·1 answer
  • Why are the offspring produced by sexual reproduction different than their parents?
    10·1 answer
  • A non metal which is good conductor of electricity
    10·2 answers
  • When the sun shines and heats something, that energy is called-
    15·2 answers
  • Covalent bonds involve the sharing of?
    10·1 answer
  • Cuál es la principal diferencia entre la química orgánica y la inorgánica?
    14·1 answer
  • Starch is a natural polymer composed of
    10·2 answers
  • Drag each label to the correct location. Each label can be used more than once.
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!