Answer:
Helium is less dense. Because helium is lighter than air, a helium balloon rises, just as an air bubble rises in more dense water
Explanation:
Also why not. It just is.
Answer:
This is due to the fact that helium has a lower density. A helium balloon rises like an air bubble in more dense water because helium is lighter than air. Another gas lighter than air is hydrogen, which is even lighter than helium.
Explanation:
The same quantity of each solute is added to water. Which solution will have the greatest number of H30+ ions at equilibrium?
(1 point)
O weak acid
O strong acid
O strong base
O weak base
What is mechanical energy?
The energy that is associated with the motion or position of an object
The energy that travels in waves from the moon
Any energy that travels through a medium like water
The stored energy in a substance like oil or gasoline
Answer:
The energy that is associated with the motion or position of an object
or simply kinetic or potential Energy
The difference between Physical/Chemical properties and Physical/Chemical changes
Physical changes can be reversed and chemical changes can’t be reversed. A physical property is a characteristic which can be identified without changing the substance but to identify a chemical property, you do have to change the substance.
11.Three atoms of element X react with an element(s) Y from group VIA. What
would be the chemical formula between X and Y.
Element “X” belongs to family 2A, meaning it is part of the family that includes elements such as Be and Mg. These elements will all have 2 valence electrons and can be represented by the following Lewis diagram:
Element “Y” belongs to family 5A, meaning it is part of the family of elements that includes elements such as N and P. These elements will all have 5 valence electrons and can be represented by the following Lewis diagram:
Atoms from these two families will usually react with each other by losing or gaining valence electrons to create stable ions (an ion is what we call an atom/particle that has a charge). These stable ions form by the atoms either losing or gaining electrons until they have the same number of valence electrons as the nearest Noble Gas. This means that each ion will have a full valence shell (usually consisting of 8 electrons), often referred to as a “stable octet”, and this process of creating stable ions is often called the “octet rule”.
Atoms with fewer that 4 valence electrons will normally have a weak hold on their valence electrons and will tend to lose their valence electrons when forming ions.
Atoms with 4 or more valence electrons will normally have a strong hold on their valence electrons and will tend to gain electrons when forming ions.
The charge on the ion arises from the fact that, initially, the atom is electrically neutral because it has the same number of electrons (negative charges) as protons (positive charges). By losing electrons, the atom will end up with more protons (positive charges) than electrons (negative charges) and will form an ion with an overall positive charge. By gaining electrons, the atom will end up with more negative electrons than positive protons becoming an ion with an overall negative charge.
So, an atom of element “X”, with only 2 valence electrons, must lose its 2 valence electrons (which will be gained by element “Y”) to form a stable ion with a 2+ charge (losing two electrons leaves the ion with 2 more positive charges (protons) than negative charges, so a net charge of 2+).
An atom of element “Y”, with 5 valence electrons, must gain 3 electrons (from element “X”) to form a stable ion with a 3- charge (gains 3 extra negative charges).
We can show this process using Lewis diagrams:
From this set of diagrams you can see that in order to create stable ions of both “X” and “Y” we need these atoms to react with each other in a 3:2 ratio (we need 3 atoms of X for every 2 atoms of Y). This means that the resulting chemical formula of the compound will be:
Now, we will look at a short cut that can help you figure this out without having to draw Lewis diagrams.
Compounds are electrically neutral, meaning they must contain equal numbers of positive and negative charges. For compounds consisting of oppositely charged ions, this means that the total charge of the negative ions must be equal to the total charge of the positive ions. In other words the ions must combine in a ratio that makes their charges add to zero.
If we look at the compound we just made, X3Y2, we can confirm this:
So, now you can you predict the formula of simple ionic compounds:
from the family of elements, determine the number of valence electrons each element has
determine the charge of the ions that each atom will form using the octet rule (or look on the periodic table, most will tell you the stable ionic charges that each element can form)
determine the ratio of positive ions to negative ions that results in an overall charge of zero
Example,
What is the formula of a compound produced when an element from family 3A combines with an element from family 7A?
Blood has a mass-volume percent of NaCl of 0.9%. What mass (g) of NaCl is present in a liter of blood
The mass (g) of NaCl that is present in a liter of blood is 0.347g.
HOW TO CALCULATE MASS:
The mass of a substance can be calculated by multiplying the decimal mass-volume of the substance by its molar mass. According to this question, Blood has a mass-volume percent of NaCl of 0.9%. This means that 0.9/100 = 0.009g of NaCl is present in each 100g of blood. Molar mass of NaCl = 23 + 35.5 = 38.5g/molMass of NaCl in a liter of blood = 38.5 × 0.009Mass of NaCl in a liter of blood = 0.347g of NaCl. Therefore, The mass (g) of NaCl that is present in a liter of blood is 0.347g.Learn more at: https://brainly.com/question/15743584?referrer=searchResults
2. Calculate the heat of combustion of C6H14(l) in kJ/mol if 1.66 g of C6H14(l) were ignited in a calorimeter containing 2750. g H2O. A 3.54˚C temperature rise was observed. The calorimeter constant is 11.2 kJ/˚C. The specific heat of water is 4.184 J/g˚C.
This problem is describing the combustion experiment where by the heat of combustion of 1.66 g of liquid C6H14 can be calculated via calorimetry. The calorimeter (C=11.2kJ/°C) contains 2750. grams of water with a temperature rise of 3.54 °C, it means we can calculate the total heat released by the combustion of this hydrocarbon via:
[tex]Q_{combustion}=-(Q_{calorimeter}+Q_{water})[/tex]
Because the heat of combustion is released to the water and the calorimeter. Next, we break down each heat and subsequently plug in the given values:
[tex]Q_{combustion}=-(11200\frac{J}{\°C}*3.54\°C +2750.g*4.184\frac{J}{g\°C}*3.54\°C )\\\\Q_{combustion}=-80,379J=-80.4kJ[/tex]
After that, we calculate the moles of C6H14 by considering the given mass and its molar mass (86.18 g/mol):
[tex]n=1.66g*\frac{1mol}{86.18g} =0.01926mol[/tex]
And finally, we divide the total heat of combistion by the moles to get the heat of combustion:
[tex]\Delta H_{comb}=\frac{-80.4kJ}{0.01926mol} =4,174\frac{kJ}{mol}[/tex]
Learn more:
https://brainly.com/question/14317568https://brainly.com/question/14154214omg y'all pls so much help me!!!
1. H2SO4
2. MGNO3
their %
How do scientists analyze the TRAPPIST system?
Answer:
A team led by Michaël Gillon at the University of Liège in Belgium detected the planets using transit photometry with the Transiting Planets and Planetesimals Small Telescope (TRAPPIST) at the La Silla Observatory in Chile and the Observatoire de l'Oukaïmeden in Morocco.
Explanation:
This is just how the TRAPPIST system was discovered.
Here's the link about the information you need:
https://www.nasa.gov/press-release/nasa-telescope-reveals-largest-batch-of-earth-size-habitable-zone-planets-around
What type of bond is between NaCL?
Answer:
Ionic Bonds
Explanation:
Ionic bonds usually occur between metal and nonmetal ions. For example, sodium (Na), a metal, and chloride (Cl), a nonmetal, form an ionic bond to make NaCl.
I NEED HELP
so is for example
FeO + H2O ---> Fe(OH)2
And
Fe + 2H20 ---> Fe(OH)2 + H2
The same? Same thing for other metals
Answer:
no
Explanation:
because when is iron oxide + water given you iron hydroxide while the other one is Iron plus 2 moles of water giving you iron hydroxide and hydrogen
What would be the bond angle if the molecular geometry were bent and had only one lone pair of electrons
120°
Bent molecular geometry
Examples H2O, SO2
Point group C2v
Coordination number 2
Bond angle(s) 90°<θ<120°
2KClO3 —> 2KCl + 302 this equation represents both a ___ reaction AND a(n) ___ reaction.
A. combustion; decomposition
B. single replacement; combustion
C. combustion; oxidation-reduction
D. decomposition; oxidation-reduction
Answer:
option D--Decomposition; oxidation-reduction
Answer: A. Combustion; decomposition
Explanation: I took it on a quiz and got it right!
I need help with this question
What causes a change in speed or direction?
A) Balanced Force
B) Net Force
C) Force
Answer:
force i think
Explanation:
Are bath bombs pure substances or mixtures
Answer:
Yes.
Explanation:
Bath bombs are usually made from three key ingredients: baking soda, citric acid and cornstarch, said Frankie Wood-Black, an instructor in chemistry at Northern Oklahoma College and an experienced bath-bomb maker. Often, bath bombs also include dyes and perfumes, and sometimes they have epsom salt.
Answer: yes
Explanation:
a substance that can be broken down into simpler substances
Answer:
compound
Explanation:
hope this hepls
According to Dalton, atoms cannot be SELECT ALL THAT APPLY a Created b Destroyed c Subdivided d Bonded
Answer:
The answer is subdivided,created or destroyed
Holding a marshmallow near a campfire flame causes it to turn brown even if the marshmallow does not touch the flame. Why does this happen?
A.
Dust blowing through the air causes the marshmallow to brown.
B.
Hot air in the atmosphere cooks the marshmallow.
C.
Heat radiates from the fire and cooks the marshmallow.
D.
Smoke and soot from the fire cause the marshmallow to brown.
Answer:
The answer is, C. Heat radiates from the fire and cooks the marshmallow.
Answer:
C Heat radiates from the fire and cooks the marshmallow.
Explanation:
Heat can be transferred through space through the process of radiation. The marshmallow is toasted because heat radiates from the fire and cooks the marshmallow.
⚠️⚠️⚠️⚠️HELPPP⚠️⚠️⚠️⚠️
A 250 kg rock falls off a cliff and comes to a rest on the ground, which is 40m below the cliff. At what point is the rock’s kinetic energy at maximum?
Answer:
at 39m
Explanation:
because thats where gravitational potential energy has been acting on it the most before it hits the ground.
pretty sure btw
please help I attached an image
Answer:
B
Explanation:
Nonmetals have nearly full valence shells and try very hard to get that last few electrons to complete their valence shell. This allows them to achieve noble gas stability. This is why they have high electronegativities and electron affinities.
what kind of molecule is a polymer??
Answer:
macromolecules
Explanation:
Polymer is composed of molecules called macromolecules that have multiple of simpler chemical units called monomers.
Indique cuáles son las unidades de la molaridad *
eq-g/m³
eq-g/L
mol/cm³
mol/L
Answer:
hm
Explanation:
sodium chloride is a compound of sodium and chlorine. which of these elements is the alkali metal and which is the halogen. why
Answer:
Chlorine is a halogen and sodium is an alkali metal.
Explanation:
Which is one factor that adds to the greenhouse effect?
a decrease in the amount of dust in the atmosphere
a decrease in the amount of water on Earth’s surface
an increase in gases in the atmosphere that absorb heat
an increase in the amount of solar radiation that reflects into space
Answer:
C
Explanation:
Edge 2022 trust the process
Knowing about the greenhouse effect we have that what intensifies this effect is an increase in gases in the atmosphere that absorb heat.
What is the greenhouse effect?Greenhouse effect is a natural atmospheric phenomenon responsible for the maintenance of life on Earth. Without the presence of this phenomenon, the temperature on Earth would be very low, around -18ºC, which would make the development of living beings impossible.
Thus, the main cause of the greenhouse effect is industrialization. Due to this process, the burning of fossil fuels has intensified in recent centuries. The main products of the combustion reaction of these reagents are the gases mentioned above as the main ones for the greenhouse effect.
See more about greenhouse effect at brainly.com/question/1577730
What list only includes physical properties
[tex] \large \text{Answer} \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ [/tex]
Boiling points,conductivity and colours contain only physical properties
If an organic compound has a carbonyl group and a hydroxyl group, with the carbonyl group connected to two R groups, is it considered an alcohol or a ketone? Or can it have properties of both?
Answer:
A carboxyl group (COOH) is a functional group consisting of a carbonyl group (C=O) with a hydroxyl group (O-H) attached to the same carbon atom. Carboxyl groups have the formula -C(=O)OH, usually written as -COOH or CO2H.
if the student finds the weight of the sodium chloride to be 28.5g,calculate the number of particles.(Na=23,Cl=35.5)
Answer:
2.93×10^23
Explanation:
molecular formula of NaCl is 58.5
58.5gof NaCl=6.023×10^23
28.5g of NaCl= 6.023×10^23÷58.5×28.5
= 2.93×10^23
can someone help me with this question!!
Answer:
A Because sodium chloride can break down the table sugar
Explanation:
hi
Is the partial pressure of o2 higher in water or the air?
How much heat is required for 10 g of steam specific heat
capacity = 2.01 J/gºC) at 120°C to be heated to 160°C?
Answer:
145°C is allowed
Explanation:
step step by step explanation