Answer:
the element is lead
Explanation:
the atomic number of lead is 82.
number of protons 82
number of electrons 82
If you do not recall the exact date of an event, it is okay to use a general time reference instead.
Please select the best answer from the choices provided
T
F
Answer:
True
Explanation:
Sorry if this is late lol
Answer:
The answer is True.
Explanation:
Did not copy
what is vascuoles ?
Answer:
Vacuoles are essentially enclosed compartments which are filled with water containing inorganic and organic molecules including enzymes in solution, though in certain cases they may contain solids which have been engulfed.
Explanation: i hoped this helped :)
Answer:
vacuole
Explanation:
a space within a cell that is empty of cytoplasm
vacuole is a membrane-bound
Convert 5.4g of NaCl to moles
Answer:
.0924 moles of NaCl
Explanation:
So you know you have 5.4 g of NaCl and you need to know how many moles there are in this amount of NaCl
You'll need to find the atomic mass of the compound NaCl to help you solve for moles Sodium (Na) on the periodic table has a mass of 22.99 Chlorine (Cl) on the periodic table has a mass of 35.45Add these two together----> 22.99 + 35.45 = 58.44
Now you can calculate for moles
Written-out method:
5.4 grams of NaCl | 1 mole of NaCl
| 58.44 grams NaCl = .0924 moles of NaCl
Plug into calculator method:
(5.4 g of NaCl/ 58.44g NaCl= .0925 moles)
. If you apply heat to the copper bar, its density will
Answer:
Decrease
Explanation:
Density is defined as the mass per unit volume. Density is highly influenced by temperature.
The density of metals and copper is inversely proportional to the temperature, it means density of copper decreases with an increase in temperature or when heated. This is so because when the copper is heated, the copper atoms start vibrating faster that allows the collision of atoms with each other faster and occupying more volume than before. As the copper atoms occupy more volume, the density of copper decreases.
Hence, the correct answer is "On applying heat the density of copper decreases".
The human eye cannot see anything less than 40 micrometers in size. What is this length in meters?
Answer:
4e-5 is the length in meters
Have a nice day! :)
Weather is not the same as climate. Which claim
identifies the main difference between these two concepts?
A. The main difference is how both are measured
B. Only weather includes information about the
temperature
C. Only climate includes information about
precipitation
O D. The main difference is the length of time over
which both are measured
Answer:
b. only weather includes information about the temperature
A balloon containing methane gas has a volume of 1.03 L at 99.0 °C . What volume will the balloon occupy at 198 °C ?
Answer:
The balloon will occupy a volume of 1.32L.
Explanation:
Given the following data;
Original Volume, V1 = 1.03L
Original Temperature, T1 = 99°C
New Temperature, T2 = 198°C
To find new volume V2, we would use Charles' law.
Charles states that when the pressure of an ideal gas is kept constant, the volume of the gas is directly proportional to the absolute temperature of the gas.
Mathematically, Charles is given by;
[tex] VT = K[/tex]
[tex] \frac{V1}{T1} = \frac{V2}{T2}[/tex]
Converting T1, from Celsius to Kelvin = 273 + 99 = 372K
Converting, T2, from Celsius to Kelvin = 273 + 198 = 471K
[tex] \frac{V1}{T1} = \frac{V2}{T2}[/tex]
Making V2 as the subject formula, we have;
[tex] V_{2}= \frac{V1}{T1} * T_{2}[/tex]
[tex] V_{2}= \frac{1.03}{372} * 471[/tex]
[tex] V_{2}= 0.0028 * 471[/tex]
V2 = 1.32L
Therefore, the balloon will occupy a volume of 1.32L at 198°C
What gets heavier in an electrochemical cell?
O A. The cathode
B. Negative ions
O C. The salt bridge
O D. The anode
Answer:
A. the cathode
Explanation:
Answer:
A. The cathode
Explanation:
a p e x
What type of reaction heats the water to generate steam in a nuclear power plant
1. As an electron in an atom moves from a higher energy state to a lower energy state, the atom
(A) becomes a negative ion
(C) releases energy
(B) becomes a positive ion
(D) absorbs energy
Answer:
(C) releases energy
Explanation:
From Bohr's model of the atom, we can understand the energy transitions involved when an electron moves from one energy level to another.
An electron in an energy level has a definite amount of energy associated with it at that level. When electrons change state, they must absorb or emit the exact amount of energy which will bring them from initial to final states. When the electron is excited, it moves from the ground state to an excited state, it must must absorb energy. On returning from an excited state, energy is emitted.(C) releases energy
From Bohr's model of the atom:
We can understand the energy transitions involved when an electron moves from one energy level to another.
An electron in an energy level has a definite amount of energy associated with it at that level. When electrons change state, they must absorb or emit the exact amount of energy which will bring them from initial to final states. When the electron is excited, it moves from the ground state to an excited state, it must must absorb energy. On returning from an excited state, energy is released or emitted.Therefore, option C is correct.
Learn more:
brainly.com/question/13822373
can someone help me im doing chemistry right now and I have a question which I have no idea how to solve and I need to show work it it needs to be shown in scientific notation
(7.6x10^-1)+(2.0x10^-2)
2.
_______ properties depend on the amount of
matter present
Answer:
extensive properties
Explanation:
,such as mass and volume, depend on the amount of matter being measured. Intensive properties, such as density and color, do not depend on the amount of the substance present. Physical properties can be measured without changing a substance's chemical identity.
What is the charge on an electron?
Answer:
Electrons have a negative charge
hope this was helpful (plz vote brainliest, I would appreciate it!) :)
HELP PLEASE
Describe and illustrate how liquids are different then the other states of matter.
Explanation:
There are four natural states of matter: Solids, liquids, gases and plasma. ... Solids also have a high density, meaning that the particles are tightly packed together. Liquids. In a liquid, the particles are more loosely packed than in a solid and are able to flow around each other, giving the liquid an indefinite shape.
Mass can be changed into energy in a ____ reaction
A)Chemical
B)Nuclear
The human eye cannot see anything less than 40 micrometers in size. What is this length in meters?
Answer:
0.00004
Explanation:
i dont have one its just i know
I NEED HELP ASAPPPP!!!!
Is a styrofoam ball heavier than a rock?
Is water heavier than a ping pong ball?
Is a gold ring heavier than a pencil?
Is oil heavier than water?
Is a large log heavier than a small rock?
Answer:
Styrofoam could be heavier than a rock depending on how much weight you put on it,
Water is heavier than a ping pong ball,
A gold ring is not heavier than a pencil,
Oil is heavier than water because of the combined mass.
A large log is heavier than a small rock.
Explanation:
A sample of ammonia gas has a volume of 3213 mL at 11°C and a pressure of 822 torr. What will the volume of the gas be in liters if the
moles of gas and the temperature do not change but the pressure changes to 2.33 atm?
Answer:
We are given:
v1 = 3.2 L v2 = x L
p1 = 822 torr OR 1.08 atm p2 = 2.33 atm
t1 = t2 = 284 k
From the Ideal gas equation:
PV = nRT
Since the number of moles (n), universal gas constant (R) and Temperature (T) are constant
PV = k (where k is a constant)
it can also be written as:
P1V1 = k --------------------------(1)
Similarly,
P2V2 = k (where k is the same constant as before)----------(2)
Solving for V2:
From (1) and (2):
P1V1 = P2V2
Replacing the variables
1.08 * 3.2 = 2.33 * x
x = (1.08 * 3.2)/2.33
x = 1.5 L (approx)
Therefore, the final volume of the solution will be 1.5L
If you are given 22.990 g of sodium and 12.011 g of carbon, which sample do you expect to have more particles?
Answer:
they are expected to have the same particles because their masses are the same with there molar mass
Calculate mass of an object if its density is 22.6 g/cm3 and it occupies volume of 5 cm3.
plz answer quickly if you know the answer... i will mark you brainliest! :)
Answer:
okay so I'm confused for the 5 cm3 but all you have to do is multiply those 2 numbers
Answer:
it is 113g
Explanation:
the formula you have to use here is mass=density*volume
sooo I multiplied it for u and gave the answer
Which element in period 5 has the largest atomic radil
Answer:
francium is the answer
Explanation:
It should be noted that the element in period 5 has the largest atomic radius is Francium.
What is an atomic radius?It should be noted that an atomic radius simply means the measure of the size of the atom from the center of the nucleus.
In this case, the element in period 5 has the largest atomic radius is Francium while Helium has the smallest radius.
Learn more about atomic radius on:
https://brainly.com/question/15255548
7. The image shows the effects of exposing the plants to different color of
lights. The size of the plant was measured and the number of leaves were
counted if they are alive or dead. Size of plants and number of leaves are
Size of Plant
Number of Leaves
Living or Dead?
science or
What’s the answer?
Answer:
An apple, potato, and onion all taste the same if you eat them with your nose plugged
Explanation:
what is the volume in cubic meter and in cubic decimeter of 2.0mol of nitrogen on gas at 1000c and 100,000pa? (R=8.31j/molk)
Given parameters:
Number of moles of Nitrogen = 2.0mole
Temperature of the gas = 1000c
Pressure on the gas = 100000Pa
Gas constant R = 8.31J/molK = 0.082atmdm³mol⁻¹k⁻¹
Unknown:
Volume in cubic meter and cubic decimeter = ?
Solution:
The ideal gas law is given as;
PV = nRT
where P is the pressure on the gas
V is the volume of the gas
n is the number of moles
R is the gas constant
T is the temperature of the gas
Let us convert to appropriate units;
1000°C to K;
K = 1000 + 273 = 1273K
100000Pa to atm;
101325Pa = 1atm
100000Pa = 0.99atm
Input the parameters and solve for the unknown;
0.99 x V = 2 x 0.082 x 1273
V = 210.9dm³
to m³;
1000dm³ = 1m³
210.9dm³ = [tex]\frac{210.9}{1000}[/tex] = 0.21m³
Order these chemical species by increasing of an aqueous solution of each. That is, imagine making an solution of each species. Select next to the species that makes the solution with the lowest . Select next to the species that makes the solution with the next higher , and so on. Notice that some of the rankings have been filled in for you already. Also notice that water is on the list. For that particular case, just compare the of pure water to the of the other solutions.
Species Relative PH of 0.1M aqueous solution
HCOOH
CIO2^-
HCOO^-
H2O
H3PO4
H2PO4
H2PO4^-
H3O^-
HClO2
Answer:
H3O^+ < HClO2 < H3PO4< HCOOH < H2PO4^-<CIO2^-<H2O< HCOO^-
Explanation:
The pH of a solution refers to the negative logarithm of it's hydrogen ion concentration. Generally, the hydrogen ion concentration of an acid is always greater than that of its conjugate base. Hence, the conjugate acid always has a lower pH than the conjugate base.
This can be seen in the species, H3O^+ and H2O, HClO2 and ClO2^- etc.
What factor is mostly responsible for the form of matter?
time
temperature
pressure
weather
Temperature is mostly responsible for the form of matter. For instance, when raising the temperature you're adding energy. This energy gives the individual molecules and atoms the ability to overcome the forces that hold them together. This can be seen when a solid turns into a liquid or a liquid turns into a gas. However, when you're lowering the temperature you're removing energy. The lack of energy results in less movement from the atoms. Gases condense into liquid because the atoms don't have enough energy to stay away from each other. Liquids solidify because the atoms don't have enough energy to slide past each other and they get stuck in place. So in conclusion, temperature determines how how much energy atoms have that allow them to move at different speeds which determines the state of matter.
Helppppppp plssss guysss
Answer:
3 - coefficient
2 subscripr
6 total #
cl- element symbol
An aqueous solution is in equilibrium with a gaseous mixture containing an equal number of moles of helium, carbon dioxide, and nitrogen. Rank the relative concentrations of each gas in the aqueous solution from highest to lowest. An aqueous solution is in equilibrium with a gaseous mixture containing an equal number of moles of helium, carbon dioxide, and nitrogen. Rank the relative concentrations of each gas in the aqueous solution from highest to lowest.
[CO2][CO2] > [He][He] > [N2][N2] [N2][N2] > [CO2][CO2] > [He][He] [CO2][CO2] > [N2][N2] > [He][He] [He][He] > [N2][N2] > [CO2][CO2]
Answer:
[CO2] > [N2] > [He]
Explanation:
The relative concentration of CO2, N2 and He depends on the solubility of each gas in water. The more soluble in water a gas is, the greater its concentration in aqueous solution.
Among the gases listed, CO2 is most soluble in water hence it is expected to have the greatest concentration in solution followed by N2. Helium gas is insoluble in water hence it has the least concentration in the aqueous solution.
What else heats the Earth when Permafrost melts?
Answer:
As those microbes thrive, they will release large amounts of methane, another climate-warming greenhouse gas. ... By the year 2100, they estimated, thawing permafrost could release enough carbon dioxide and methane to raise the average global temperature by 0.13 to 0.27 degree C (0.23 to 0.49 degree F). pls mark me brainlest :(
Explanation:
D 14 3
N
7
What is the number of protons, neutrons, and electrons?
Answer:
14
Explanation:
For example, silicon has 14 protons and 14 neutrons. Its atomic number is 14 and its atomic mass is 28. The most common isotope of uranium has 92 protons and 146 neutrons. Its atomic number is 92 and its atomic mass is 238 (92 + 146).
How many total hydrogen atoms are in CH3OOH?
Answer:
4
Explanation:
In CH3OOH, there is H3, which means 3 hydrogen atoms, but there is also an H at the end, which means another hydrogen atom.
3 + 1 = 4