A 7.28 g sample of chromium metal was heated to produce chromium oxide. The weight of the compound was 10.63 g. What is the percent chromium in this compound?
Answer:
68.48%
Explanation:
The percent mass of an element in a compound tells us about the amount of such element contributed to the total compound.
In this case, 7.28 g sample of chromium metal was heated to produce chromium oxide with weight of 10.63 g. The percent mass of chromium in chromium oxide can be calculated by using the formula:
%mass of Cr = mass of Cr/mass of Chromium oxide × 100%
%mass of Cr = 7.28/10.63 × 100
%mass of Cr = 0.6848 × 100
%mass of Cr = 68.48%
20 POINTS
What is true about the Sun, light bulbs, and flames?
AThey are all made of fire.
BThey are all made by people.
CThey are all found in nature.
DThey are all sources of light energy.
Answer:
D
Explanation:
Light blubs are not made of fire.
The sun wasnt made by humans.
You cant find Light bulbs in nature.
Meaning it is D.
Why do gases diffuse more quickly than liquids?
Choose the correct answer.
A) Liquids can be compressed easily.
B)The particles in gases are not mobile.
C)Liquids are always at lower temperatures than gases.
D)Gas particles move rapidly and have space between them.
Answer:
D)Gas particles move rapidly and have space between them.
Explanation:
Matter exists in three states namely: solids, liquids and gases. The particles contained in these three states are different from one another. In the gaseous state, the particles are FAR APART from one another i.e. space exists and they move at a very fast rate in contrast to the particles of a liquid, which have less space and move slower.
This rapid movement of gas particles within a less restricted space accounts for the reason why gaseous substances DIFFUSE more quickly than liquids.
1 point
Which element requires the least amount of energy to remove its valence electron(s)?
barium
chlorine
oxygen
carbon
TRUE OR FALSE? Alloys are used more than pure metals because they are generally softer and less likely to react with air or water.
Alloys are used much more than pure metals because they are generally stronger and less likely to react with air or water...
So I would say false
which stimulate causes high energy emotional elation dehydration and damage serotonin producing neurons
Answer:
ecstasy
Explanation:
A scientist is considering formaldehyde (HCHO) for use in an experiment. She is studying the strength of triple bonds in molecules. Is
ormaldehyde a good choice for her to use? Why?
A. Yes, HCHO has three triple bonds.
B. Yes, HCHO has one triple bond.
C. No, HCHO has a double bond but no triple bonds.
D. No, HCHO has only single bonds.
A scientist who collects and analyzes DNA from a crime scene is a
Answer:
forensic scientist
Explanation:
forensic science is the discipline in which professionals use scientific means to analyze physical crime evidence. this evidence is then presented in court in order to help determine the innocence or guilt of a specific suspect.
Answer:
Its a forensic scientist :D
Explanation:
I took a test and got it wrong but it showed the right answer and its a forensic scientist
(don't ask how i got it wrong i was rushing!!)
The periodic table is organized into groups and periods of elements. The characteristics of a certain group of elements are listed below. Which of these elements is in this group?
Characteristics of a group of elements
•is shiny
•is solid at room temperature
•has atoms with two valence electrons
A-silicone
B-lithium
C-strontium
D-aluminum
Answer:
C:Strontium
Explanation:
When a material gains thermal energy and melts, it is undergoing a physical change.
Answer:
True, it undergoes a physical change.
Explanation:
A physical change is a change that does not change the chemical makeup of a material. This includes altering its shape.
What is the best-known feature of sedimentary
rocks?
A. ripple marks
B. fossils
C. graded bedding
D. cross-bedding
Answer:
option is (b)
Explanation:
please mark me as brilliant
If the hydronium ion concentration of a substance is 1.0 X 10-6 M, what would be the pH of that substance??
Show/Describe your work.
formal charge of hcooh
Answer:
What is the question?
The atomic masses of 20Ne (90.48 percent), 21Ne (0.27 percent), and 22Ne (9.25 percent) are 19.9924356, 20.9938428, and 21.9913831 amu, respectively. Calculate the average atomic mass of neon. The percentages in parentheses denote the relative abundance
Answer:
20.180042 amu
Explanation:
From the question given above, the following data were obtained:
Isotope A (20Ne)
Mass of A = 19.9924356 amu
Abundance (A%) = 90.48%
Isotope B (21Ne):
Mass of B = 20.9938428 amu
Abundance (B%) = 0.27%
Isotope C (22Ne):
Mass of C = 21.9913831 amu
Abundance (C%) = 9.25%
Average atomic mass of Neon =.?
The average atomic mass of Neon can be obtained as follow:
Average atomic mass = [(mass of A × A%)/100] + [(mass of B × B%)/100] + [(mass of C × C%)/100]
= [(19.9924356 × 90.48)/100] + [(20.9938428 × 0.27) /100] + [(21.9913831 × 9.25) /100]
= 18.0891557 + 0.05668338 + 2.03420294
= 20.180042 amu
Therefore, the average atomic mass of Neon is 20.180042 amu
All the following are physical properties of metals EXCEPT
a. malleability
c. conductivity
b. brittleness
d. ductility
Explanation:I think it's option b) brittleness
I hope this might help u
What type of bond would be expected between Mg and Ti?
A.hydrogen bond
Bionic bond
C.covalent bond
D.metallic bond
What is the formula mass for (NH4)2C2O4
Answer:
124.1 g/mol
Explanation:
just facts
Answer:
124.1 g/mol
Explanation:
To calculate formula mass, multiply the subscript of each element in the formula by the element's atomic weight (relative atomic mass) found on the periodic table. The unit for formula mass is either u or Da (Daltons).
What volume. In liters, of H2O(g) measured at STP is produced by the combustion of 15.63 g of natural gas (CH4) according to the following equation? CHale) +20269) CO2 + 2H2008)
Answer:
V = 43.95 L
Explanation:
Given data:
Mass of CH₄ decomposed = 15.63 g
Volume of H₂O produced at STP = ?
Solution:
Chemical equation:
CH₄ + 2O₂ → 2H₂O + CO₂
Number of moles of CH₄:
Number of moles = mass/molar mass
Number of moles = 15.63 g/ 16 g/mol
Number of moles = 0.98 mol
Now we will compare the moles of H₂O with CH₄.
CH₄ : H₂O
1 : 2
0.98 : 2×0.98 = 1.96 mol
Volume of hydrogen:
PV = nRT
1 atm × V = 1.96 mol × 0.0821 atm.L/mol.K × 273.15 K
V = 43.95atm.L / 1atm
V = 43.95 L
PLEASE HELP ME! I am confused on this.
Answer:
Mohammed has less kinetic energy
Explanation:
m=Kg
V= m/s
KE= kinetic energy = J
the way you work out the answer is:
KE = 1/2 × m × v squared
What is the specific rotation of a sample of carvone that is an equal mixture of the R and S enantiomers
Answer:
Zero
Explanation:
An an equal mixture of the R and S enantiomers of carvone is called a racemic mixture.
In a racemic mixture, the R enantiomer rotates plane polarized light in one direction while the S enantiomer rotates plane polarized light in another direction.
This cancels out the rotation due to each enantiomer since they are equal in magnitude but opposite in direction leading to a specific rotation of zero for the racemic mixture.
What element has 2 occupied principals of energy levels
PLEASE HELP!! Circuit A consist of two wires and a battery. Circuit B consist of the same strength battery and the same type of wires, but it also contains a light bulb. Which circuit has more resistance?
Answer:
light bulb B
Explanation:
more resistance
PLEASE HELP IM TIMED
Which of the following is not an oxidation-reduction reaction?
Upper X e upper F subscript 6 (s) right arrow upper X e upper F subscript 4 (s) plus upper F subscript 2 (g).
2 upper C s (s) plus upper I subscript 2 (g) right arrow 2 upper C s upper I (s).
2 upper H subscript 2 upper S upper O subscript 4 (a q) plus 2 upper B a (upper O upper H) subscript 2 (a q) right arrow 2 upper B a upper S upper O subscript 4 upper H subscript 2 upper O (l).
Upper Z n (s) lus 2 upper A g upper N upper O subscript 3 (a q) right arrow upper Z n (upper N upper O subscript 3) subscript 2 (a q) plus upper A g (s).
Answer: choice 2
Explanation:
List 5 foods that contain bacteria?
what elements make up duralumin( an alloy)?
Answer:
In addition to aluminium, the main materials in duralumin are copper, manganese and magnesium.
Answer:
The original composition has been varied for particular applications; it may contain about 4 percent copper, 0.5–1 percent manganese, 0.5–1.5 percent magnesium, and, in some formulations, some silicon.
Which energy transformation produces electricity and is least likely to negatively impact the environment?
Generating electricity from a natural gas-fired power plant
Generating electricity from a natural gas-fired power plant
Generating electricity from a coal-fired power plant
Generating electricity from a coal-fired power plant
Generating electricity from a nuclear power plant
Generating electricity from a nuclear power plant
Generating electricity from a solar panel system
Generating electricity from a solar panel system
electricity from solar panels
Explanation:
All other options produce something after or during the time electricity is made. That something is gas. Not solar
A beverage manufacturer wants to increase The solunility of carbon dioxide in its carbonated drinks as beverages produced which action will increase the solubility of CO2 gas the most
A. Decreasing the pressure on it
B. Increasing stirring
C. Decreasing its temperature
D. Increasing its temperature
Answer: C
Explanation:
9.Ammonium nitrate (NH4NO3) can decompose to form gaseous water, nitrogen, and oxygen. What is the sum of the coefficients in the balanced chemical equation
Answer:
the sum of the coefficients in the balanced chemical equation is 9
Explanation:
The computation of the sum of the coefficients in the balanced chemical equation is shown below:
here is the balanced chemical equation
[tex]2NH_4NO_3 \rightarrow 4H_2O)g) + 2N_2(g) + 1O_2(g)[/tex]
Now the sum is
= 2 + 4 + 2 + 1
= 9
hence, the sum of the coefficients in the balanced chemical equation is 9
and, the same is to be considered
25. Which of the following statements concerning atomic structure is/are correct?
1. The nucleus contains most of an atom's mass.
2. The nucleus contains all the positive charge of an atom.
3. Electrons surround the nucleus and account for the majority of an atom's volume.
1 only
2 only
3 only
2 and 3
1, 2, and 3
Answer:
It would be 2 and 3
The image shows the structure of an atom, I hope it helps :)
To see the number of atoms of an element in a given molecule we need to multiply stoichiometry to the number that is written on the foot of the element that is stoichiometry. Therefore, the correct option is option 2,3.
What is atom?Atom is the smallest particle of any element, molecule or compound. Atom can not be further divided. Atoms contains nucleus in its center and electron that revolve around the atom in fixed orbit.
In the nucleus, proton and neutron are present. Electron has -1 charge while proton has +1 charge. Neutron is neutral that is it has no charge. So overall the charge of nucleus is due to only proton, not by neutron. The nucleus contains all the positive charge of an atom. Electrons surround the nucleus and account for the majority of an atom's volume.
Therefore, the correct option is option 2,3.
To know more about atom, here:
https://brainly.com/question/13518322
#SPJ2
Calculate the number of atoms present in .20 moles of H20.
Answer:
20 moles = (96.7+)
345%20 moles inter = h20
h2+345%20 moles
kalkadanc = jani+CARSORI
564 MOLES
Explanation
we have to plus the moles that we can get the answer and u should now the formula of kalkadanc and just % will get to the correct answer.
i think u may understand and this is the correct answer i had practice this too much