Answer:
helium is denser than air
Answer:
For air, which has a molar mass of 29.0 g/mol, this gives a density of 1.18 g/l. Helium, which has a mass of 4.00 g/mol, has a density of 0.164 g/l.
An atom with which atomic diagram is most similar to calcium?
Answer:
C
Explanation:
Calcium is an element with a total of 20 electrons.
It has 4 shells with a configuration of:
2, 8, 8, 2
Option C is the most similar to calcium but the number of shells is not complete.
It still requires two more shells with 8 and two electrons respectively.
Which molecule has the strongest forces of attraction between molecules?
Dipole-dipole interactions are the strongest intermolecular pressure of attraction.
Answer: Dipole-dipole interactions are the strongest intermolecular force of attraction.
Explanation:
The breaking and forming of bonds between atoms in substances results in changes in the _______ contained in the substances.
Answer:
Electrons
Explanation:
The breaking and forming of bonds between atoms in substances results in changes in the number of electrons in the substance.
Atoms combined in order to share, gain or lose electrons for it to be stable. The noble gases have a set up configuration which makes them stable. All atom tend to mimic the noble gases.how can air produce a pressure
IN OWN WORDS NOT FROM GOOGLE
Answer:
Gas pressure is caused when gas particles hit the wall of their contains. the more often the particles hit the walls, and the faster they are moving when they do this , the higher the pressure .
Explanation:
A 75.0 gram sample of water at 25.0 degrees Celsius is mixed with a 100. Gram sample of water at 60.0 degrees Celsius. What is the final temperature of the water?
Answer:
The final temperature of the water = 45°C
Explanation:
Heat lost = heat gained
Heat lost by water at 60°C = m₁CΔT₁
Heat gained by water at 25°C = m₂CΔT₂
where m₁ is mass of water at 60°C = 100.0 g; m₂ is mass of water at 25°C = 75.0 g
C, specific heat capacity of water = 4.18 J/g°C
ΔT₁ = (60 - T); ΔT₂ = (T - 25); T = final temperature of the water
m₁CΔT₁ = m₂CΔT₂
100 * C * (60 - T) = 75 * C * (T - 25)
-100T + 6000 = 75T - 1875
-(100T + 75T) = -(6000 + 1875)
175T = 7875
T = 45°C
Therefore, final temperature of the water = 45°C
Carl makes the table below to determine the number of atoms of each element in the chemical formula 4Ca(ClO3)2.
A table with 3 columns and 2 rows. The first column labeled element has entries calcium, chlorine, oxygen. The second column labeled calculation has entries 1 times 4 , 1 times 2, 3 times 2. The third column labeled total atoms has entries 4, 2, 6.
What mistake did Carl make?
Answer:
calcium chloride oxide
Answer:
He did not multiply the chlorine and oxygen atoms by the coefficient 4
Explanation:
I just took the quiz
If 30cm³ of 0.45 mol dm3 HCl reacted with NaOH, how many moles of HCl reacted?
Moles HCl reacted : 0.0135
Further explanationMolarity shows the number of moles of solute in every 1 liter of solute or mmol in each ml of solution
[tex]\large {\boxed {\bold {M ~ = ~ \dfrac {n} {V}}}[/tex]
Where
M = Molarity
n = Number of moles of solute
V = Volume of solution
So to find the number of moles can be expressed as
n = V x M
The volume of HCl 30 cm³=3.10⁻² dm³
Molarity of HCl = 0.45 mol/dm³
so moles HCl reacted :
[tex]\tt n=3.10^{-2}\times 0.45=0.0135[/tex]
please someone help me its due today thanks :D
Answer:
D
Explanation:
All of the above are great examples!
"Endothermic reactions are those which absorb heat during the reaction."
Sea-Floor Spreading1. The arrows on the figure show the ocean floor spreading from the ridge. What are three kinds of evidence scientists have found to support this idea?
A. B. C.
I NEED HELP
Predict the products for the following chemical reaction: H2 + O2 →
a. H30
b. H20
c. H2OH
d. OH + OH
O a
A unit of substance that contains the Avogadro number of atoms or molecules is referred to as a ____________ of the substance.
Answer:
A unit of substance that contains the Avogadro number of atoms or molecules is referred to as a mole of the substance.
Explanation:
The mole (symbol: mol) is the unit of measurement for amount of substance in the International System of Units (SI). A mole of a substance or a mole of particles is defined as exactly 6.02214076×1023 particles, which may be atoms, molecules, ions, or electrons. In short, for particles, 1 mol = 6.02214076×1023.
Suggest whether water freezing is an endothermic or exothermic process. Can you explain your suggestion?
How many moles of
C
O
2
COX
2
will be produced from
97.0
g
97.0 g97, point, 0, start text, space, g, end text of
C
3
H
8
CX
3
HX
8
, assuming
O
2
OX
2
is available in excess?
Answer:
Im highy
Explanation:
Classify each organic compound based on the functional group it contains.
ether
carboxylic acid
ester
alcohol
Molecular Structure
Type of Compound
I-O-I
Η Ο
1 10
C-C-0-H
1
H
H
-I
H
II
H
1
H-C
1
H
H
1
-C
1
H
1
H
1
H
1
H
H
I
H-C
1
H
H H
I
C-0-C-H
1
1
H H
1
H-CC-O-H
1
H H
Answer:
H2C2O1
Explanation:
Answer:
Carboxylic Acid
Ester
Ether
Alcohol
Explanation:
From smallest to largest put these in order of their atomic radius Mg, Ba,
Sr, Ca
O Ca, Mg, Ba, S
O Ra, Sr, Ca, Mg
Mg, Ca, Sr, Ra
Mg, Sr, Ra, Ca
Answer:
b
Explanation:
i jus did it
Ernest Rutherford built on the work of previous scientists and improved the accuracy of the atomic model. What part of the atom is Rutherford
credited for discovering?
A.) The protons
B.) The electrons
C.) The nucleus
D.)The electron cloud
(10 POINTS PLS ANSWER IF U KNOW)
Is the coloring of the peppered moths an example of competition, differential reproductive success, or inherited variation? Explain why.
Answer:
Competition
Explanation:
Peppered moths get their color in lieu to become the fittest among all so that they can survive easily. During industrial age, when pollution suddenly became high these moths changed their color through evolution in order to save themselves from their predators.
PLS GIVE BRAINLIEST
PLEASE HELP!!!!! NEED HELP ASAP!!!!!
Write the chemical formula for the ionic compounds below
EXAMPLE- Calcium Phosphide= Ca3P2
Magnesium chloride=
Aluminum Fluoride=
Lithium Bromide=
Potassium Sulfide=
Answer:
down below
Explanation:
MgCl2
AlF3
LiBr
K2S
The _____________ is similar to a vacumn cleaner because it cleans up cell waste.
a
endoplasmic reticulum
b
lysosome
c
mitochondria
d
cell wall
How many atoms of each element are in one molecule of 2-heptanone
Answer:
A chemical structure of a molecule includes the arrangement of atoms and the chemical bonds that hold the atoms together. The 2-HEPTANONE molecule contains a total of 21 bond(s) There are 7 non-H bond(s), 1 multiple bond(s), 4 rotatable bond(s), 1 double bond(s) and 1 ketone(s) (aliphatic).
Answer:
Explanation:
CH3 provides 1 Carbon
C4 provides 4 carbons
COC provides 2 more
Total 7 Carbons
======================
COCH3 Provides 1 Oxygen
======================
CH3 provides 3 Hydrogens
C4H8 provides 8 hydrogens
COCH3 has 3 more hydrogens
Total 14 hydrogens
The answer should be B.
You should note that there are no brackets which means you only need to read the small numbers going down behind each element. You might have to read that sentence a could of times, but it is important to know.
Help plzzzz urgent !!!!!!!!!!!!!!
Answer: B < C < A
Explanation:
Ok so things that have the lowest pka are the strongest acids. the higher the pka the less acidic it is.
Atoms and ions are all the same.
Answer:
Yes they are
Explanation:
Which atom in the following sets has the larger atomic radius?
a. Rn, Ne, Ar, Kr
b. Hg, Cs, Po, W
c. Mg, P, Al, Ar
Answer:
A.Rn,Ne,Ar,Kr.......
what are chiral carbon
Answer:
A chiral carbon is a carbon bonded to four different groups ( four groups as carbon forms four bonds). The molecules formed are non superimposible on its mirror image.
Which of the following are soluble in water: salt, gravel, or pepper
Which of the following laboratory procedures best illustrates the law of conservation of mass? (Assume the product of the reaction includes the mass of any unused reactants.) (3 points)
Reacting 12 g of C with 32 g of O2 to form 44 g of CO2
Weighing 100 g of Cu powder and 100 g of Fe filings
Heating 100 g of CaCO3 to produce 56 g of CaO
Dissolving 10 g of NaCl in 100 g of water
Answer: Reacting 12 g of C with 32 g of O2 to form 44 g of CO2
Explanation: I took the test just now, and the law of conservation of mass means to energy and that is exactly what they do in this answer!
Answer:
A
Explanation:
what percent of a sample of a radioactive element whose half life=5.0 years will decay after 25 years?
Answer:
Calculate the rate of decay constant for U-238 if its half-life is 4.468 × 109 years. Answer: If the problem is referring to the half-life, then the ratio of = 0.5 because half of the original sample has already undergone decay.
Explanation:
Match the term with the definition.
Condensation
Evaporation
Sublimation
Freezing
A) A phase change from a gas to a liquid
B) A phase change from a solid to a gas
C) A phase change from a liquid to a gas
D) A phase change from a liquid to a solid
[Please Hellp!]
when molecules move they react by cooling down.
True or False?
Answer:
false
Explanation:
when molecules move they heat up
Describe two physical properties of matter and how those properties are measured.