Answer:
The correct answer is option c.
Explanation:
Density is defined as mass present in unit volume of the substance.
Given that density of pure lead is more than that of the sample.
Density of lead =
Density of sample =
Since, we know that density is directly linked to mass of the substance. So with decrease in density of substance indicates that mass present in unit volume of the substance has also decreased.
The reason behind the less density of sample from lead was that, that it was made up lead and other light substance.
B They both dissociate completely, with little or no reverse reactions.
C They both remain intact when placed in water, with no dissociation taking place.
D They both dissociate completely, with reverse reactions constantly taking place.
2 What happens when the kinetic energy of molecules increases so much that electrons are released by the atoms, creating a swirling gas of positive ions and negative electrons?
A Matter changes to a solid state.
B Matter changes to a liquid state.
C Matter changes to a plasma state.
D Matter changes to a gaseous state.
3 Consider a balloon that has a volume V. It contains n moles of gas, it has an internal pressure of P, and its temperature is T. If the balloon is heated to a temperature of 15.5T while it is placed under a high pressure of 15.5P, how does the volume of the balloon change?
A It doubles.
B It stays the same.
C It increases greatly.
D It decreases slightly.
1) Answer is: B They both dissociate completely, with little or no reverse reactions.
Some of strong acids: HNO₃(nitric acid), HCl(hydrochloric acid), H₂SO₄(sulfuric acid), HI(hydroiodic acid). Strong bases are: sodium hydroxide (NaOH), barium hydroxide (Ba(OH)₂).
For example, hydrochloric acid, completely dissociate in water and give large amount of hydrogen ions (H⁺): HCl(aq) → H⁺(aq) + Cl⁻(aq).
Sodium hydroxide completely dissociate in water:
NaOH(aq) → Na⁺(aq) + OH⁻(aq).
2) Answer is: C Matter changes to a plasma state.
Plasma is a an ionised gas with highly electrical conductivity.
In solid, molecules are closely packed, stiff and do not changes of shape or volume. Solid object (for example iron) does not take on the shape of its container.
Liquids have definite volume, but no fixed shape.
Gases (for example nitrogen and neon) not have definite volume and fixed shape, it depends on its container.
3) Answer is: B It stays the same.
p₁ = P; initial pressure.
p₂ = 15.5 P; final pressure.
V₁ = V: initial volume.
V₂ = ?: final volume.
T₁ = T; initial temperature.
T₂ = 15.5T; final temperature.
The combinated gas law: The volume of a given amount of gas is proportional to the ratio of its Kelvin temperature and its pressure: p₁·V₁/T₁ = p₂·V₂/T₂.
P·V/T = (15.5P · V₂) / 15.5 T.
V₂ = V₁ = V.
Answer:
1). B
2). C
3). B
Explanation:
Answer:
15 moles
Explanation:
b. The nucleus has a negative charge
c. The atom has a dense nucleus
d. Alpha particles can pass through a thin sheet of gold foil
e. All of the above are correct regarding the gold foil experiment
The percent by mass of carbon in acetic acid (HC2H3O2) is calculated using the molar masses of its constituent elements. Upon calculation, it is determined that the percent by mass of carbon in acetic acid is 40.00%.
To calculate the percent by mass of carbon in acetic acid (HC2H3O2), we need to use the molar masses of the elements involved. The formula for acetic acid includes two carbon atoms, four hydrogen atoms, and two oxygen atoms. Using the given molar masses (carbon: 12.01 g/mol, hydrogen: 1.008 g/mol, oxygen: 16.00 g/mol), the molar mass of acetic acid can be calculated as follows:
Adding these together gives the molar mass of acetic acid as 60.052 g/mol.
To find the percent by mass of carbon, we take the total mass of carbon in the compound and divide it by the total molar mass of the compound:
(24.02 g/mol / 60.052 g/mol) × 100% = 40.00%
Therefore, the percent by mass of carbon in acetic acid is 40.00%.
Answer:
70 kilometers per hour
Explanation:
280 kilometers ÷ 4 hours (7:00 pm - 3:00 pm = 4 hours) = 70 kilometers per hour
Hope this helps! Sorry if wrong. You are loved and you are beautiful/handsome!
-Bee