Answer:
The atomic number on the Periodic Table will tell you how many protons are in the nucleus of each atom.
Explanation:
number of electrons and protons should be equal in a neutral atom. Because each electron has a -1 charge, and each proton a +1 charge, the number of each must be the same for the net charge to equal zero.
Which of the following describes metallic character on the periodic table? Question 1 options: A) It increases as you move right to left within a period and down a group on the periodic table. B) It increases as you move left to right within a period and down a group on the periodic table. C) It increases as you move left to right within a period and up a group on the periodic table. D) It increases as you move right to left within a period and up a group on the periodic table.
Answer:
D
Explanation:
Metallic character decreases as you move across a period in the periodic table from left to right. This occurs as atoms more readily accept electrons to fill a valence shell than lose them to remove the unfilled shell. Metallic character increases as you move down an element group in the periodic table. This is because electrons become easier to lose as the atomic radius increases, where there is less attraction between the nucleus and the valence electrons because of the increased distance between them.
Which star has the highest surface temperature
A. blue star
B. yellow star
C. white star
D. red star
Answer:
The blue star is the hottest star.
Explanation:
Red stars are cooler than the sun, with surface temperatures of 3,500 K for a bright red star and 2,500 K for a dark red star. The hottest stars are blue, with their surface temperatures falling anywhere between 10,000 K and 50,000 K
Which of the following describes scientists?
О
A. People with only one perspective
B. People with similar personalities
C. People from different backgrounds
D. People with perfect understanding of science
what is the most appropriate unit to measure the following; the length of a football field. b) the diameter of a tennis ball
Explanation:
a) m (metre)
b) mm (millimeter)
What is the oxidation state of S in HSO4^2-? (A.P.E.X)
I think there is a typo because I've never seen HSO4 2- before in my life. It should be HSO4-. For that, H is 1+ and each Oxygen is 2-0 totaling 8-. So the oxidation state of sulfur +1 - 8 = 7
So the oxidation state of sulfur is +6
A 0.085 M solution of a weak acid has a pH of 2.68. Determine the Ka value for this acid.
Answer:
The answer for ka is 5.26x10^-5
Explanation:
Fill in 5.26x10^-5
19. If 23.4 grams of hydrogen gas were produced by the reaction below, how many grams of aluminum chloride were produced? (2 points) 2 Al + 6 HCl yields 2 AlCl3 + 3 H2 516 g AlCl3 774 g AlCl3 1030 g AlCl3 1550 g AlCl3
Answer:
1040
Explanation:
you can use the mole to mole ratios of aluminum chloride and hydrogen gas,you first have to find the number of moles of hydrogen gas..the number of moles of hydrogen gas are 11.7(23.4/2)
2AlCl3+3H2
2 : 3
x :11.7
3x/3=23.4/3
x=7.8g/mol
then find the number of grams of aluminum chloride
m=n×mr
=7.8×133.341
=1040g
I hope this helps and sorry if it's wrong
(Q008) Two physical properties of minerals both result in smooth, flat surfaces with specific angles between them. The first property is externally visible and is the result of how the mineral forms; the second is inherently internal and is the result of breaking a sample of the mineral. These properties are called
Answer: Crystal habit and cleavage.
Explanation:
When two physical properties of minerals both bring about smooth, flat surfaces that has specific angles between them.such that the first property is externally visible and is the result of how the mineral forms while the second property is internal and is the result of breaking a sample of the mineral, it should be noted that the properties are refered to as the crystal habit and cleavage.
It should be noted that the cleavage refers to the tendency of crystalline materials to be able to split along the structural planes.
100cm³ of ethane gas diffuses through a porous plug in 100 seconds.What is the molecular mass of the gas Q if 100cm³ of the gas diffuses through the same plug in 121 secknds under the same condition?(C=12.0,H=1.0)
Answer:
The molar mass of gas Q is 43.923 g/mol
Explanation:
The given volume of ethane gas that diffuses through a porous plug in 100 seconds = 100 cm³
Therefore;
The rate of diffusion of ethane gas through the porous plug, [tex]v_{ethane}[/tex], is given as follows;
[tex]v_{ethane}[/tex] = (100 cm³/100 s) = 1 cm³/s
The molar mass of ethane, C₂H₆ = 2×12 g/mol + 6×1 g/mol = 30 g/mol
The given volume of gas, Q, that diffuses through a porous plug in 121 seconds = 100 cm³
∴ The rate of diffusion of the gas, Q, [tex]v_Q[/tex] = 100/121 cm³/s
Graham's Law of diffusion states that the rate of diffusion of a gas is inversely proportional to the square root of the molecular mass of the gas
Mathematically, we have;
[tex]\dfrac{v_A}{v_B} =\sqrt{\dfrac{m_B}{m_A} }[/tex]
Where;
[tex]v_A[/tex] = The rate of diffusion of gas A
[tex]v_B[/tex] = The rate of diffusion of gas B
[tex]m_A[/tex] = The molar mass of the gas A
[tex]m_B[/tex] = The molar mass of the gas B
Therefore, for ethane and gas Q, measured under the same condition, we have;
[tex]\dfrac{v_{ethane}}{v_Q} =\sqrt{\dfrac{m_Q}{m_{ethane}} }[/tex]
[tex]\dfrac{1 \ cm^3/s}{\dfrac{100}{121} \ cm^3/s} =\sqrt{\dfrac{m_Q}{30 \ g/mol} }[/tex]
[tex]m_Q = \left ({\dfrac{121}{100} } \right) ^2 \times 30 \ g/mol = 43.923 \ g/mol[/tex]
The molar mass of gas Q, [tex]m_Q[/tex] = 43.923 g/mol.
Calculate the amount of mole of iron produced from the reaction of 15.9 grams of iron oxide.
Fe2O3 + 3 H2 +2 Fe + 3 H2O
Answer:
0.19875
Explanation:
nFe2O3=0.099375
nFe=2nFe2O3=0.19875
Freezing point depression is:
A. When a substance freezes and then quickly drops in temperature.
B. When a substance drops in temperature until it freezes, then quickly rises in temperature but stays frozen.
C. When a substance does not need to be as cold as normal in order to freeze.
D. When a substance must be colder than normal in order to freeze.
Freezing point depression is when a substance must be colder than normal in order to freeze.
Freezing point is that temperature where a liquid substance becomes a solid i.e. freezes. Freezing point depression is the process whereby the temperature at which a substance freezes is lowered.Freezing point depression often occurs when a solute is added to a solvent. This reduces its freezing point. Since temperature is reduced, in other words, this means that the substance must become colder than normal for it to start freezing.
Hence, freezing point depression is when a substance must be colder than normal in order to freeze.
Learn more at: https://brainly.com/question/2785367
D. When a substance must be colder than normal in order to freeze.
Explanation:
hey love, I just took the quiz on this for founder's education. I hope this helped.
As a person BAC level increase it becomes difficult for them to judge their vehicle distances and speed
Answer:
TRUE
Explanation:
The blood alcohol content is also known as the blood alcohol level or the blood alcohol concentration. It is defined as the measurement of the alcohol intoxication in the body and is used for the legal or the medical purposes.
When the BAC increases in the person's body, the person started to loose clear vision, loss of short term memory, poor muscle coordination, impaired perception and face difficulty in concentrating. Thus it becomes very difficult for a person to drive a car or ride a bike whose BAC has increased.
The driver cannot properly judge the distances between the vehicle and the speed of the vehicle.
Hence the answer is TRUE.
Atom A and Atom B have the same number of protons and neutrons, but they do not have the same number of electrons. ASAP
Answer:
They will be considered ions of the same element.
Explanation:
Ions form from elements when they gain or loss an electron, causing the number of protons (positively charged) to be unequal to the number of electrons (negatively charged), resulting in a net charge.
If there are more electrons than protons (from an element gaining 1 or more electrons), the ion is negatively charged and is called an anion.
If there are more protons than electrons (via the loss of electrons), the ion is positively charged and is called a cation.
what volume of 2.0 m hcl contains 0.50 mol hcl?
Answer:
the volume of the acid is 250 mL.
Explanation:
Given;
number of moles of the Hcl acid, n = 0.5 mol
concentration of the acid, C = 2.0 M = 2 mol/L
let the volume of the acid = V
The volume of the acid is calculated by applying the following equation;
n = CV
V = n/C
[tex]V= \frac{0.5 \ mol}{2 \ mol/L}[/tex]
V = 0.25 L
V = 250 mL
Therefore, the volume of the acid is 250 mL.
Which of the following are held together by nonpolar covalent bonds?
The Periodic Table
A. Atoms of phosphorus (P) and chlorine (CI)
B. Atoms of chlorine (CI)
C. Atoms of chlorine (CI) and magnesium (Mg)
D. Atoms of magnesium (Mg)
Answer:
Answer: Atoms of chlorine (CI) and magnesium (Mg)
Answer: Atoms of chlorine (CI) and magnesium (Mg)is your answer
how can you separate mixture of suphur, nacl and nh4cl
Answer:
Ammonium chloride, iron ,Sulphur and salt mixed together... they can be separated in the following methods.
1. Ammonium chloride is separated by sublimination... NC4CI is sublimable. Heat the mixture in a china dish and collect the funds of NC4CI (sublimable substance)
2. Bring a magnet close to the remaining mixture. Iron is magnetic substance and thus, it will be attracted towards the magnet. Iron is separated.
3. Sulphur is insoluble in water and salt is soluble. Add water to the remaining mixture and then wait for sedimentation. Separate the sulphur by decantation.
4. Heat the filtered salt solution to obtain salt.
What is the molecular geometry of a molecule made of two atoms that share one pair of electrons and have no lone electrons pairs?
trigonal pyramidal
linear
trigonal planar
bent
Answer:
linear
Explanation:
Actually I consulted various sources too and that was the most sought answer,I just decided to answer you before studying it too
A student is asked to convert measurements from meters to millimeters and from millimeters to meters. His answers are
shown in bold in the choices shown below. On which choite did he make a mistake?
9070 mm = 90.7 m
652,222 mm= 652.222 m
37,500 mm = 37.5 m
1.02 x 106 mm = 1020 m
Answer:
The first one
Explanation:
9070 mm = 90.7 m
9070mm is actually equal to 9.07m
A student measures the volume of a small irregularly- shaped stone. Which apparatus must be used? a. a measuring cylinder containing water and a ruler only. b. a measuring cylinder containing water only. c. an empty measuring cylinder and a ruler only. d. a ruler only.
Answer:
a measuring cylinder containing water only.
Explanation:
If we want to measure the volume of an irregular object. We need a properly calibrated measuring cylinder filled with water of known volume.
The irregular object is now inserted into the measuring cylinder containing water and the change in the volume of water is noted. The volume of the irregular object is now obtained as;
New volume of water - initial volume of water.
Hence, only a measuring cylinder filled with water is required to measure the volume of a small irregularly- shaped stone.
Which group of elements is generally unreactive? O A. Noble gases O B. Halogens O C. Alkali metals D. Nitrogen family
Answer:
Nobles Gases Are the group of elements which are generally unreactive
I Hope its right if not then Sorry, have a wonderful day :)A cactus needle is a structure made of different tissues that work together to protect the plant from animals that might want to eat it. What level of body organization does a cactus needle represent?
A. Cell
B. Organ
C. Cell system
D. Body system SUBMIT
10. As electrons move through the electron-transport chain,
they lose energy, which is used to form
A. NAD.
B. ADP
C. ATP.
D. GBP
Answer:
NAD
Explanation:
mark me brainlist please
Answer:
They lose energy which is used to form ATP
Which statement is true?
A. In an exothermic reaction, the energy of the products is the same as the energy of the reactants.
B. In an endothermic reaction, the energy of the products is the same as the energy of the reactants.
C. In an endothermic reaction, the energy of the products is greater than the energy of the reactants.
D. In an exothermic reaction, the energy of the products is greater than the energy of the reactants.
Exothermic reaction is where there is release of energy during a reaction
The enthalpy of exothermic reaction is negative
The relation between energy of products, reactants and enthalpy of reaction is
Enthalpy of reaction = sum of enthalpy of formation of products - sum of enthalpy of formation of reactants .
As enthalpy of reaction is negative, it means the enthalpy of products is less than the enthalpy of reactants so answer is :
In an exothermic reaction the energy of the product is less than the energy of the reactants.
C.
An endothermic reaction is a reaction that absorbs heat from the surroundings. That means that the energy of the system must increase. Therefore, the answer must be C as the products should have higher energy than the reactants.
What is valence of helium
How many molecules are in 35.5 grams of carbon dioxide?
Answer:
you have to use the avogadro's constant of 6.023×10^23 to calculate the number of molecules of carbon dioxide.and you also have to use the molecular mass which is 44.
35.5/44×6.023×10^23
=4.85×10^23
I hope this helps and sorry if it's wrong
Realiza los cálculos para determinar la cantidad de KOH 90%, que se necesita para preparar 100 ml de solución 1N.
Answer:
6.23 KOH 90% son necesarios
Explanation:
Una solución 1N de KOH requiere 1equivalente (En KOH, 1eq = 1mol) por cada litro de solución.
Para responder esta pregunta se requiere hallar los equivalentes = Moles de KOH para preparar 100mL = 0.100L de una solución 1N. Haciendo uso de la masa molar de KOH y del porcentaje de pureza del KOH se pueden calcular los gramos requeridos para preparar la solución así:
Equivalentes KOH:
0.100L * (1eq / L) = 0.100eq = 0.100moles
Gramos KOH -Masa molar: 56.1056g/mol-:
0.100moles * (56.1056g/mol) = 5.61 KOH se requieren
KOH 90%:
5.61g KOH * (100g KOH 90% / 90g KOH) =
6.23 KOH 90% son necesariosWhat are you most likely to observe when an endothermic reaction is taking place?
Answer:
An endothermic reaction is when heat is needed by the reaction, so it draws heat from its surroundings, making them feel cold. Just like a ice pack.
g) silver nitrate + magnesium chloride → silver chloride + magnesium nitrate
Answer:
AgNo3+Mgcl2--->Agcl2+Mg(No3)2
I hope this helps
from the equation 2PbO + C = 2Pb + CO2, detemine which one is reactant is oxidised and which is reduced.
Answer:
Explanation:
C is oxidised because C up to C+4
PbO is reduced because PbO from Pb2+ down to Pb0
Answer:
lead (Pb) is reduced carbon is oxidized
PLZ HELP ME Which of the following lists the levels of body organization in order from most basic to most complex?
A Tissues, organs, body systems, cells
B. Cells, tissues, organs, body systems
C. Cells, organs, body systems, tissues
D. Tissues, cells, organs, body systems
Answer:
It is B
Explanation:
I was able to find my school notes and double-check. I hope you have a nice day!
