Instructions: Use the periodic table to answer the questions below:
1) How many periods are there on the periodic table?
2) How many groups are there on the periodic table?
3) Which element is found in Group 2 and Period 3?
4) Which element is found in Group 17 and Period 2?
5) Which element is found in Group 10 and Period 4?
6) Which element is found in Group 18 and Period 6?
7) Which element is found in Group 1 and Period 7?
8) Which element is found in Group 14 and Period 6?
Answer:
1. 7 periods
2. 18 groups
3.Magnessium
4.Fluorine
5.Nickel
6.Radon
7.Francium
8.Lead
Explanation:
Pick one answer do not put any links please
Which of the following could be added to a solution of potassium fluoride to prepare a buffer?
A) ammonia
B) potassium acetate
C) hydrochloric acid
D) sodium fluoride
E) sodium hydroxide
Which of the following are things that may change during an experiment?
Answer:
The things that are changing in an experiment are called variables. A variable is any factor, trait, or condition that can exist in differing amounts or types.
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When performing a neutralization reaction, how should students test the solution to be sure which is the acid and which is the base?
Explanation:
La reacción entre un ácido y una base se llama neutralización. Cuando en la reacción participan un ácido fuerte y una base fuerte se obtiene una sal y agua. Si una de las especies es de naturaleza débil y la neutralización se produce en disolución acuosa también se obtiene su respectiva especie conjugada y agua.
(True or false) The blood carries hormones to target tissues around the body so the hormones can control the activity of those cells
Answer:
True
Explanation:
Answer:
True
Explanation:
Hormones are chemical messengers secreted into blood or extracellular fluid by one cell that affect the functioning of other cells. Most hormones circulate in blood, coming into contact with essentially all cells. However, a given hormone usually affects only a limited number of cells, which are called target cells.
If those same 25 grams are carbon are reacted, how many moles of carbon dioxide will be produced?
Answer:
I'm am so cool I'm depressed tho so yeah good job lady
Explanation:
Select the correct answer.
Which of the following is the Arrhenius equation?
A.
K=AeEa/RT
B.
K = -AeEa/RT
c.
K = Ae-Ea/RT
D.
K = -Ae-Ea/RT
Answer:
The answer is C
Explanation:
A tube contains hydrogen and oxygen gas. Its total pressure is known to be 4.53 atm. It's the pressure of the hydrogen is 2.7 atm, what us the pressure of the oxygen in atm?
Answer:
1.83 atm
Explanation:
Total pressure is the sum of partial pressures, so the pressure of hydrogen and pressure of oxygen add to equal 4.53 atm
4.53 = 2.7 + Po
Po = 4.53 - 2.7 = 1.83 atm
Which of the following is a TRUE statement?
a.
A molecule always has three types of elements present
b.
Compounds always include the elements hydrogen and sodium
c.
Compounds include things we use in our everyday lives
d.
All elements prefer to hang out with other elements and form molecules
Answer:
b
Explanation:
The nicotine molecule cannot make ionic bonds. Change nicotine into a different molecule, one that can now can make ionic bonds.
Answer:
See explanation
Explanation:
Nicotine is a covalent molecule. Recall that covalent molecules are not soluble in water and do not have any kind of ionic interaction.
Let us recall that nicotine contains a nitrogen atom having a lone pair of electrons. When nicotine reacts with HCl, this lone pair is protonated to form the ionic compound called nicotine hydrochloride.
C₁₀H₁₄N₂ + HCl --------> C₁₀H15N₂Cl
What is the formula to find
moles
Explanation:
these are the formula that u need to know
1. moles= concentrate × volume
2. moles = mass / mr
3. moles = volume in dm3 / 24dm^3
4. moles = Pressure in pa × Volume in m3 / 8.031 × temperature in K
hope this helps :)
Can yall help me with this one, thanks!
Answer:
Element atom molar mass Total % composition
Na 1 23 40 57.5 %
O 1 16 40 40%
H 1 1 40 2.5 %
The given compound is NaOH.
Na : number of atom= 1
Molar mass= 23 g/mol
Total mass of NaOH = 40 g/mol
% composition by mass = [tex]\frac{\text {mass of atom}}{\text {Total mass}}\times 100=\frac{23}{40}\times 100=57.5\%[/tex]
O : number of atom= 1
Molar mass= 16 g/mol
Total mass of NaOH = 40 g/mol
% composition by mass = [tex]\frac{\text {mass of atom}}{\text {Total mass}}\times 100=\frac{16}{40}\times 100=40\%[/tex]
H : number of atom= 1
Molar mass= 1 g/mol
Total mass of NaOH = 40 g/mol
% composition by mass = [tex]\frac{\text {mass of atom}}{\text {Total mass}}\times 100=\frac{1}{40}\times 100=2.5\%[/tex]
Earthquakes and what kind of plate boundary movement cause them?
Do you think it is a good idea for all scientists to use the same periodic table of elements? Why or why not?
As altitude increases, what happens to air pressure the choices are it fluctuates, it increases, it decreases or it stays the same
Answer:
it decreases
Explanation:
It is a common saying the pressure decreases with height. This means that as altitude increases, the pressure of air decreases. The higher you go above sea level, the pressure becomes lesser.
This is as a result of decrease in the amount of air above sea level and hence a decrease in the density of air as altitude increases.
Hence, with increasing altitude, pressure decreases.
Answer:
It decreases
Explanation:
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An organism whose cell contains a nucleus.
Answer:
Eukaryotes
Explanation:
A container at equilibrium contains the following concentrations: [Hz] - 0.30 M and [HI]
0.90 M. The equilibrium constant is equal to 6.0. What is the concentration of I2 at
equilibrium?
Hzig) + 1218 = 2 Hle)
Answer: The concentration of [tex]I_2[/tex] at equilibrium is 0.45 M
Explanation:
Equilibrium constant is defined as the ratio of concentration of products to the concentration of reactants each raised to the power their stoichiometric ratios. It is expressed as [tex]K_c[/tex]
For the given chemical reaction:
[tex]H_2(g)+I_2(g)\rightarrow 2HI(g)[/tex]
The expression for [tex]K_c[/tex] is written as:
[tex]K_c=\frac{[HI]^2}{[H_2]^1[I_2]^1}[/tex]
[tex]6.0=\frac{(0.90)^2}{(0.30)^1\times (I_2)^1}[/tex]
[tex][I_2]=0.45M[/tex]
Thus concentration of [tex]I_2[/tex] at equilibrium is 0.45 M
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Answer:
6)B.C,Ge,Pb,Si
7)A.Be,Mg,Sr
8)D.arsenic,calcium
9)B.Group 13,period 3
Over millions of years silt washed into a lake formed layers of sedimentary rock. What type of rock was likely formed?
Answer:
Explanation:
siltstone
Over millions of years, silt washed into a lake formed layers of sedimentary rock. What type of rock was likely formed? A type of detrital sedimentary rock called siltstone was the likely product of this process.
Number 8
in metals, reactivity increases ____ across a period, and in non metals reactivity increases ____ across a period.
A. to the left,to the left
B. to the left, to the right
C. to the right , to the left
D. to the right, to the right
how acceptance of responsibility influence affective in communication
Answer:
f
Explanation:
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What are the correct numbers to balance this equation......?
__NaCI2+__Col2——> __Nal2+__CoCI2
Answers:
1)not possible to balance
2) 2...2—>...2...2
3) 3...3—>...3...3
4)it’s already balanced.
Answer:
yes it is already balanced
just a tricky question!!
Explanation:
What does the charge tell you about an atom?
Brainliest!!!!!!
Answer:
The charge will tell you if the atom is neutral, positive, or negative. "The charge of an atom is the number of protons minus the number of electrons."
You had a closed tank of air at a pressure of 4 atm and temperature of 20 degrees Celsius. When the tank and the air are heated to 40 degrees Celsius, what is the pressure if the volume remains constant?
Answer:
The pressure will be 4.27 atm.
Explanation:
Gay-Lussac's law can be expressed mathematically as follows:
[tex]\frac{P}{T} =k[/tex]
Where P = pressure, T = temperature, K = Constant
This law indicates that the quotient between pressure and temperature is constant.
This law indicates that, as long as the volume of the container containing the gas is constant, as the temperature increases, the gas molecules move faster. Then the number of collisions with the walls increases, that is, the pressure increases. That is, the pressure of the gas is directly proportional to its temperature.
In short, when there is a constant volume, as the temperature increases, the pressure of the gas increases. And when the temperature is decreased, the pressure of the gas decreases.
You want to study two different states, an initial state and a final state. You have a gas that is at a pressure P1 and a temperature T1 at the beginning of the experiment. By varying the temperature to a new value T2, then the pressure will change to P2, and the following will be fulfilled:
[tex]\frac{P1}{T1} =\frac{P2}{T2}[/tex]
In this case:
P1= 4 atmT1= 20 C= 293 K (being 0 C= 273 K)P2= ?T2= 40 C= 313 KReplacing:
[tex]\frac{4 atm}{293 K} =\frac{P2}{313 K}[/tex]
Solving:
[tex]P2= 313 K* \frac{4 atm}{293 K}[/tex]
P2= 4.27 atm
The pressure will be 4.27 atm.
How many grams of Si are there in a sample of Si that contains the same number of moles as a 60.8 gram sample of P?
Answer:
55.1 g Si.
Explanation:
Hello there!
In this case, for the given mole-mole relationship, it is possible to set up the following mole ratio as the moles of Si and P are the same:
1 mol Si = 1 mol P.
Next, since one mole of silicon has a mass of 28.09 g and one of phosphorous of 31.0 g, we can set up the following expression for the mass of silicon:
[tex]60.8gP*\frac{1molP}{31.0gP}*\frac{1molSi}{1molP}*\frac{28.09gSi}{1molSi}[/tex]
Therefore, the result is 55.1 grams of silicon.
Best regards!
Organisms change energy from the environment or from their food into other types of energy. This is called what?
Answer:
Metabolism
Explanation:
This is called Metabolism.
Metabolism is a combination of spontaneous chemical reactions which release non-spontaneous energy and chemical reactions requiring energy to proceed. In order to perform cellular processes, living organisms can take energy from food, nutrients or sunlight.
How much force is needed to accelerate a 1000-kg car at a rate of 3 m/s2? a 1003 N b 0.003 N c 3000 N d 333.3 N
Answer:
Option c.
Explanation:
According to Newton's law, formula to solve this problem is:
F = m . a
Mass → 1000 kg
a → 3 m/s²
F = 1000 kg . 3m/s² → 3000 N
1 N = 1 kg . m/s² according to SI, Internation System of units.