Answer:
One way to prove that air is made of matter is to blow up a balloon. Before you add air into the balloon, it is empty and shapeless. When you puff air into it, the balloon expands, so you know it is filled with something—air is taking up space. You'll also notice that a balloon filled with air sinks to the ground.
Explanation:
What molecular geometry would be expected for BF3 and NH3?
Answer:
Boron trifluoride would have a trigonal planar geometry.Ammonia would have a trigonal pyramidal geometry.Explanation:
There are three valence electrons in a boron atom.
In boron trifluoride, the central boron atom did not achieve an octet with eight valence electrons. Rather, that boron atom would be electron deficient with only six valence electrons.
Each of the three fluoride atoms would have shared one valence electron with that boron atom, with a total of three boron-fluorine single bonds. On the other hand, all three of the valence electrons of that boron atom would be involved in bonding. Hence, there would be no extra valence electrons to act as lone pairs on that boron atom.
Hence, the central boron atom would have three electron domains (one for each boron-fluorine bond) with none of the electron domains coming from lone pairs. By the VSEPR theory, the geometry of the molecule would be trigonal planar. All four atoms in this molecule would be in the same plane.
There are five valence electrons in a nitrogen atom.
In ammonia, the central nitrogen atom is indeed able to achieve an octet (with eight valence electrons in total.) Three of the five valence electrons of nitrogen would form a total of three hydrogen-nitrogen bonds. The other two valence electrons would form a lone pair.
Hence the central nitrogen atom would have four electron domains (one for each of the three hydrogen-nitrogen bond, and one for the lone pair.) Hence, by the VSEPR theory, the geometry of this molecule would be trigonal pyramidal.
is there a better way to figure out the ratio of molecule types? What might that be?
Which additional claim can be BEST supported by the evidence from the skulls in the whale fossil record?
A.
The fossil record shows differences in the skulls of the mammals, which shows that they are from three separate species that all lived at the same time.
B.
The fossil record shows similarities in the skulls of the mammals, which shows that they must have had similar habitats and environments.
C.
The fossil record shows that some mammals evolved so that their nostrils are further at the top of their skull for better breathing while in the water.
D.
The fossil record does not give enough evidence about the mammals to determine if there is a relationship between the three skulls.
Answer:
d
Explanation:
Answer:
B
Explanation:
I think it is B because it starts out with it's nostrils so it is on the mouth causing it not to be able to breathe but over time it's nostril moved to the top of the head so they could breather better
Determine the number of moles in a 100.0g sample of water.
Answer:
5.55 moles is the answer ....
Explanation:
if 18g H2O is equal to 1 mole then 100 g H2O is how much?
100/18 which is 5.55
Answer:
5.551
Explanation:
100.0g x 1mol H20/18.015g H20 = 5.551 moles of H20
The 18.015g is from the periodic table. H = 1.008x2 = 2.016g H2
0= 15.999
15.999 + 2.016= 18.015
What is the motion of the particles in this kind of wave?
A.the particles will move up and down over large areas.
B.the particles will up and down over small areas.
C.the particles will move side to side over small areas.
D.the particles will move side to side over large areas.
Answer:
not sure sorry
Explanation:
In the equation for the orbital radii in hydrogen-like atoms, a0 is called the:
Select the correct answer below:
A. energy level
B. Bohr radius
C. nuclear charge
D. orbital constant
How do you think the artist creates sculptures that vary in color and intensity?
Answer:
Light reflected off objects. Color has three main characteristics: hue (red, green, blue, etc.), value (how light or dark it is), and intensity (how bright or dull it is). Colors can be described as warm (red, yellow) or cool (blue, gray), depending on which end of the color spectrum they fall.
Christ Crowned / Honthorst
Christ Crowned with Thorns, Gerrit van Honthorst, about 1620
Value describes the brightness of color. Artists use color value to create different moods. Dark colors in a composition suggest a lack of light, as in a night or interior scene. Dark colors can often convey a sense of mystery or foreboding.
Light colors often describe a light source or light reflected within the composition. In this painting, the dark colors suggest a night or interior scene. The artist used light colors to describe the light created by the candle flame.
Annunciation / Bouts
The Annunciation, Dieric Bouts, 1450–1455
Intensity describes the purity or strength of a color. Bright colors are undiluted and are often associated with positive energy and heightened emotions. Dull colors have been diluted by mixing with other colors and create a sedate or serious mood. In this image the artist captured both the seriousness and the joy of the scene with the dull gray stone interior and the bright red drapery.
Explanation:
Identify the problem that the cold pack must address
Just need 1-3 sentences
Answer:
A person's hand holding a cold pack on an ankle ... To determine if a reaction is exothermic or endothermic, you have to compare the ... Well, that also applies to energy of solution problems.
Explanation:
Answer:
To determine if a reaction is exothermic or endothermic, you have to compare
Explanation:
Describe 1 physical property and 1 chemical properties of a metal bicycle
Answer:
A physical property would be The metal, while a possible chemical property would be a chance of gallium. (Gallium is liquid on hot days)
Explanation:
anyone know how to do this?
How many atoms are in 1.22 moles of magnesium?
Answer:
7.34684 × 10^23 atoms
Explanation:
Well, one mole is basically
6.022 × 10^23 atoms. So 1.22 moles would be
6.022 × 10^23 ⋅ 1.22 atoms.
6.022 × 10^23 ⋅ 1.22 = 7.34684 × 10^23 atoms
The total number of atoms in 1.22 moles of magnesium is 7.34 × 10²³.
One mole of a substance is equal to 6.022 × 10²³ units of that substance (such as atoms, molecules, or ions).The number 6.022 × 10²³ is known as Avogadro's number or Avogadro's constant.Given:
1.22 moles of magnesium
[tex]1 \text{ mole}= 6.022*10^{23}\text{ atoms}\\\\1.22 \text{ moles}= 1.22*6.022*10^{23}\text{ atoms}\\\\1.22 \text{ moles}=7.34*10^{23}\text{ atoms}[/tex]
So, the total number of atoms in 1.22 moles of magnesium is 7.34 × 10²³.
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brainly.com/question/11175128
Choose the aqueous solution below with the highest boiling point. These are all solutions of nonvolatile solutes and you should assume ideal van't Hoff factors where applicable.
A) 0.075 m NaI
B) 0.075 m (NH4)3PO4
C) 0.075 m NaBrO4
D) 0.075 m LiCN
E) 0.075 m KNO2
Answer:
B. (NH₄)₃PO₄
Explanation:
Elevation of boiling point is one of the colligative properties.
Formula is: ΔT = Kb . m . i
ΔT = Boiling T° of solution - Boiling T° of pure solvent.
i = Van't Hoff factor (numbers of ions dissolved)
Kb = Ebulloscopic constant
In this case, all the m are the same so let's dissociate the salts:
NaI → Na⁺ + I⁻ i = 2
(NH₄)₃PO₄ → 3NH₄⁺ + PO₄⁻³ i = 4
NaBrO₄ → Na⁺ + BrO₄⁻ i = 2
LiCN → Li⁺ + CN⁻ i = 2
KNO2 → K⁺ + NO₂⁻ i = 2
The biggest i would have the biggest boiling point, then B is the right answer, ammonium phosphate.
You count the i, with the moles of ions, you dissociate from the salt.
Two atoms of Nh3 reacts with one N2 how many moles of Nh3 reacts with one 2.00 mole of N2
Explanation:
there are four (4)mole of Nh3 that react with N2
Baking soda has a pH of 8. Its a(n) _________ substance
Acid
Neutral
Alkaline
Powdery
(god bless!! have a wonderful and blessed day!!! i love you!! and dont forget no matter what god loves you too!!!
Answer:
it's an acid
Explanation:
because itis soda
Which of the following has a negative charge?
neutrons
electrons
nucleus
protons
Answer:
electrons have a negative charge
Explanation:
Answer:
Electrons
Explanation:
An iron nail that has rusted is an example of a chemical reaction.
True
False
Answer:
True
Explanation:
what is a method to isolate insoluble salts after a neutralisation reaction
Answer:
multiply
Explanation:
multiplacation
How many orbitals are in the subshell with the following quantum numbers: n=4,l=2,ml=−2,−1,0,1,2?
Select the correct answer below:
A. 1
B. 3
C. 5
D. 7
What are the 3 Newton laws
Answer:
The laws are: (1) Every object moves in a straight line unless acted upon by a force.
(2) The acceleration of an object is directly proportional to the net force exerted and inversely proportional to the object's mass.
(3) For every action, there is an equal and opposite reaction.
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How are the atomic number and the number of protons related to each other?
Answer:
Neutral atoms of each element contain an equal number of protons and electrons. The number of protons determines an element's atomic number and is used to distinguish one element from another. ... Together, the number of protons and the number of neutrons determine an element's mass number.
Explanation:
Calculate the number of molecules in 64.5 grams of Nitrogen monoxide, NO
N=9.933
Explanation:
no of mole = m÷mr
then ,no of molecules=n×la
Hi please help with these questions :)
Answer:
c
Explanation:
because electricity has a good conduct tha is mental
In eukaryotic cells, RNA is transcribed from DNA in the _____
ribosomes
nuclear membrane
cytosol
nucleus
Answer:
The answer is Nucleolus
Most of the mass of an atom is found in
Answer:
Most of the mass of an atom is found in the nucleus.
Explanation:
Table sugar and salt are examples of? A. mixtures B. elements C. atoms D. compounds
Answer:
The answer is compound because they consist of multiple things.
describe the three states of matter that are present when snow melts
Answer:
solid liquid and gas
Explanation:
ice is a solid then it melts to liquid and evaporates into gas
Answer:
Snow is basically water;
ice/snow is solid state
water is liquid state
vapour is gaseous state
Explanation:
2NaCl → 2Na +Cl2
What reaction is this
Answer:
Decomposition reaction
Explanation:
A single reactant breaking down to form 2 or more products is decomposition
30)
Cosmologists believe that the universe is expanding and that it has been expanding since the Big Bang. Astronomers
viewing distant stars see evidence of this expansion in which phenomenon?
A)
Red shift
B)
Blue shift
Gamma pulse
D)
Background radiation
Answer:
i did this so the next person can have brainliest
Explanation:
84.9 g of solid iron reacts with oxygen gas forming iron(III) oxide. How many moles of oxygen will react
Answer:
1.14 moles of oxygen will react
Explanation:
The balanced equation of reaction between iron and oxygen is
4 Fe + 3 O₂ → 2 Fe₂O₃
By stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of each compound participate in the reaction:
Fe: 4 molesO₂: 3 molesFe₂O₃: 2 molesThe molar mass of iron being Fe 55.85 g/mole, then the following amount of mass reacts by stoichiometry: 4 moles* 55.85 g/mole=223.4 g
You can apply the following rule of three: if by stoichiometry 223.4 grams of Fe react with 3 moles of O₂, 84.9 grams of Fe react with how many moles of O₂?
[tex]moles of O_{2} =\frac{84.9 grams of Fe*3 moles ofO_{2} }{223.4 grams of Fe}[/tex]
moles of O₂= 1.14 moles
1.14 moles of oxygen will react
Determine whether each change represents oxidation or reduction. 1) CH3CHO to CH3CH2OH 2) CH3OH to CH4 3) N2H4to N2 4) gain of electrons 5) NO-2 to NH3 6) NAD+ to NADH 7) CH4 to Co2 8) Ag+ to Ag
Answer:
1) oxidation
2) Reduction
3) Oxidation
4) Reduction
5) Reduction
6) Reduction
7) Oxidation
8) Reduction
Explanation:
Oxidation is said to have taken place when there is a positive change in the oxidation number while reduction is said to have taken place when there is a decrease in the oxidation number.
The change from CH3CHO to CH3CH2OH represents on oxidation reaction.
The change from CH3OH to CH4 is a reduction because the oxidation number of carbon changes from +2 to -4.
The change from N2H4to N2 is an oxidation because the oxidation number of nitrogen increases from -2 to 0.
The gain in electrons is a reduction because the gain of electron leads to a decrease in oxidation number.
The change from NO- 2 to NH3 is a reduction because the oxidation number of nitrogen changes from +4 to -3.
The change from NAD+ to NADH is a reduction since NAD+ is the oxidized form of the enzyme while NADH is the reduced form of the enzyme.
The change from CH4 to Co2 is an oxidation because the oxidation number of carbon changes from -4 to + 4.
The change from Ag+ to Ag is a reduction because it involves the gain of one electron and a consequent decrease in oxidation number.