Answer:
A ball is thrown straight up from a rooftop 320 feet high. The formula below describes the ball's height above the ground, h, in feet, t seconds after it was thrown. The ball misses the rooftop on its way down and eventually strikes the ground. How long will it take for the ball to hit the ground? Use this information to provide tick marks with appropriate numbers along the horizontal axis in the figure shown.
h=-16t^2+16t+320
BJECTIVE TYPE QUESTIONS
Fill in the blank spaces by choosing the correct words from the words given in list.
List : composition, heat, chemical, photosynthesis, physical
1. Heating of zinc oxide is a
change.
2. Burning of coal is a
change.
3. There is a change in state and
during a chemical change.
4. Plants make their food by the process of
5.
energy is generally given out or absorbed during a chemical change
Answer:
1.Physical change
2. Chemical change
3. Heat
4.photosynthesis
5. composition
Consider the reaction. 2HF(g)—H2(g)+F2(g). What is the value of Keq for the reaction expressed in scientific notation
Answer:
A). 2.1 × [tex]10^{-2}[/tex]
Explanation:
Given reaction,
2[tex]HF[/tex] (g) ⇄ [tex]H_{2}[/tex] (g) + [tex]F_{2}[/tex] (g)
The concentrations are as following;
[tex]HF[/tex] = 5.82 × [tex]10^{-2}[/tex] M
[tex]H_{2}[/tex] = 8.4 × [tex]10^{-3}[/tex] M
[tex]F_{2}[/tex] = 8.4 × [tex]10^{-3}[/tex] M
So,
[tex]K_{eq}[/tex] = [([tex]H_{2}[/tex] ) × ([tex]F_{2}[/tex])] ÷ [[tex]HF[/tex]]^2
Now,
We can determine the value of [tex]K_{eq}[/tex] by substituting the values in above formula:
[tex]K_{eq}[/tex] = [ (8.4 × [tex]10^{-3}[/tex] M) × (8.4 × [tex]10^{-3}[/tex] M)] ÷ [(5.82 × [tex]10^{-2}[/tex])^2
= 2.08 * [tex]10^{-2}[/tex]
= 2.1 × [tex]10^{-2}[/tex]
∵ [tex]K_{eq}[/tex] = 2.1 × [tex]10^{-2}[/tex]
Thus, option A is the correct answer.
Arrange the following bonds in order of increasing ionic character:
C - H
F - H
Br - H
Na - Cl
K - F
Li - Cl
Answer:
This is the answer
C-H, Br-H, F-H, LI-CI, Na-CI, K-F
Hope this helps.
A published hypothesis:
A: does not need to be tested
B: becomes a scientific law
C: should be tested by the scientific community
D: is accepted by the scientific community
Answer:
C
Explanation:
I hypothesis needs to be tested to know whether it is true or not. Here is the definition:
A supposition or proposed explanation made on the basis of *limited evidence as a started point for further investigation*
A gas at 100 Celsius has a volume of 33.5 L. What is its new volume after it is cooled to 25 Celsius?
Answer:
[tex]\boxed {\boxed {\sf 8.38 \ L}}[/tex]
Explanation:
We are asked to find the new volume of a gas after a change in temperature. We will use Charles's Law, which states the volume of a gas is directly proportional to the temperature. The formula for this law is:
[tex]\frac {V_1}{T_1}= \frac{V_2}{T_2}[/tex]
The gas starts at 100 degrees Celsius and a volume of 33.5 liters. Substitute these values into the formula.
[tex]\frac {33.5 \ L}{100 \textdegree C}=\frac{ V_2}{T_2}[/tex]
The gas is cooled to 25 degrees Celsius, but the volume is unknown.
[tex]\frac {33.5 \ L}{100 \textdegree C}=\frac{ V_2}{25 \textdegree C}[/tex]
We want to find the volume of the gas after it is cooled. We must isolate the variable V₂. It is being divided by 25 degrees Celsius and the inverse of division is multiplication. Multiply both sides of the equation by 25 °C.
[tex]25 \textdegree C*\frac {33.5 \ L}{100 \textdegree C}=\frac{ V_2}{25 \textdegree C}* 25 \textdegree C[/tex]
[tex]25 \textdegree C*\frac {33.5 \ L}{100 \textdegree C}= V_2[/tex]
The units of degrees Celsius cancel.
[tex]25*\frac {33.5 \ L}{100 }= V_2[/tex]
[tex]8.375 \ L = V_2[/tex]
The original measurements have 3 significant figures, so our answer must have the same. For the number we found, that is the hundredth place. The 5 in the thousandths place tells us to round the 7 up to an 8.
[tex]8.38 \ L \approx V_2[/tex]
The new volume after the gas is cooled is approximately 8.38 liters.
Question 6 I need help
The answer is zero also I suggest googling the questions there is a quizlet with the answers
Using dobereiner's triads, what conclusion could have been made about magnesium
Answer:
Triads were groups of 3 elements with similar chemical and physical properties. Beryllium, magnesium, and calcium are all earth alkalis found in the earth
Explanation:
Given: CNO2
a) Draw the Lewis structures (Do not forget to show the calculation of the number of available valance electrons)
b) Name the geometry shape
c) Indicate the polarity (polar or non-polar)
Answer:
since there are no lone pairs on the central atom, this would be a trigonal planar molecule. It's polar because the shape of it does not cancel its polarity (you can think of it as not having a balanced electronegativity pull, since the nitrogen is pulling on one side, and the oxygens are pulling on the other. It would be nonpolar if the there were 3 Oxygens).
Sorry this take a little bit long. I was a little confused by the odd valence number
Name five metal which are both dilute and memorable? class 10
Values for the molar mass of hydrogen, oxygen, and water molecules are
given in the table below. What mass of water is formed when 2 moles of
hydrogen react with 1 mole of oxygen to form water?
Molecule
Molar mass (g/mol)
H2
2.02
02
32.00
H20
18.01
A.9.00 g
B. 36.02 g
C. 2.00 g
D. 18.01 g
Answer:
36.02g bbbbbbbbbbb hbbnjkkkj
Answer:
36.02g
Explanation:
Hope this helps!
Putting rock salt on the roads during a snowstorm is an example of: A. Boiling point elevation B. Vapor pressure raising C. Vapor pressure lowering D. Freezing point depression
Answer:
The correct answer is - D. Freezing point depression.
Explanation:
When rock salt is spread over snow-covered icy roads, it generates a liquid layer over it by melting from the surface thereby lowering or depression in the freezing point below the ice.
Therefore, due to this liquid layer comes into the contact with the ice present on the road and causes other ice to melts. This keeps on decreasing the volume of the ice on the road therefore, rock salts spread on the roads during a snowstorm.
Analysis of an ore of calcium shows that it contains 13.61 g calcium and 21.77 g oxygen in a 46.28-g sample. Calculate the percent composition of this compound.
Answer:
29.41% of Calcium and 47.04% of Oxygen
Explanation:
The percent composition of an atom in a molecule is defined as 100 times the ratio between the mass of the atom and the mass of the molecule.
The mass of the molecule of the problem (Ore) is 46.28g. That means the percent composition of Calcium is:
13.61g / 46.28g * 100 = 29.41% of Calcium
And percent composition of Oxygen is:
21.77g / 46.28g * 100 = 47.04% of Oxygen
What is the name of N2C14? Explain how you determined the bond type and the steps you used to determine the naming convention for the compound.
Answer:
One way to predict the type of bond that forms between two elements is to compare the electronegativities of the elements. In general, large differences in electronegativity result in ionic bonds, while smaller differences result in covalent bonds. the bonding is covalent bcz its between the most electronegative atom nitrogen and carbon .
Since the electronegativity difference between nitrogen and chlorine is not very much so chemical bonding is the only bond between them Thus the name of N2C14 is Dinitrogen Tetrachloride and there is covalent bonding in this compound
What is chemical bonding?There are two types of bonding in chemistry, one is ionic bonding while other is covalent bonding. Ionic bonding is due to the complete transfer of electron from one element to other. While the covalent bond is due to the equal sharing of electron by each element
Metals and non metals combine to form ionic bond while the element with the same electronegativity form covalent bonding.
To name this we have to see the number of element and accordingly use di, tri and the write the name of first element and then second element's name with ide
Thus the name of N2C14 is Dinitrogen Tetrachloride and there is covalent bonding in this compound
To know more about chemical bonding, here:
https://brainly.com/question/1686358
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how do i calculate the concentration of a certain solution
Answer:
Divide the mass of the solute by the total volume of the solution. Write out the equation C = m/V, where m is the mass of the solute and V is the total volume of the solution. Plug in the values you found for the mass and volume, and divide them to find the concentration of your solution.
Which is the formula mass of (NH4)2SO4?
96.07 amu
114.12 amu
116.17 amu
132.17 amu
Answer:
132.17amu
Explanation:
(14.01+1.01 multiplied by 4)=18.05×2=36.1
36.1+32.07= 68.17
16.00×4=64
68.17+64=132.17
Answer:
132.17 amu
Explanation:
just took the test. got 100
A gas that was cooled to 200 Kelvin has a volume of 65.8 L. If its initial volume was 132.4 L, what was its initial temperature?
Answer:
Initial temperature, T1 = 99.4 Kelvin
Explanation:
Given the following data;
Initial volume, V1 = 65.8 LitresFinal temperature, T2 = 200 KelvinFinal volume, V2 = 132.4 LitresTo find the initial temperature (T1), 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' law is given by the formula;
[tex] \frac {V}{T} = K [/tex]
[tex] \frac {V_{1}}{T_{1}} = \frac {V_{2}}{T_{2}} [/tex]
Making T1 as the subject formula, we have;
[tex] T_{1} = \frac {V_{1}T_{2}}{V_{2}} [/tex]
Substituting the values into the formula, we have;
[tex] T_{1} = \frac {65.8 * 200}{132.4} [/tex]
[tex] T_{1} = \frac {13160}{132.4} [/tex]
Initial temperature, T1 = 99.4 Kelvin
Ricardo compra un gaseosa en el súper al destaparla la gaseosa comienza a salir espuma y vuelca la mitad al piso ¿Por qué puede ocurrir eso?
Answer:
Las bebidas gaseosas como las gaseosas están hechas de un soluto de dióxido de carbono gaseoso en un líquido. La solubilidad del dióxido de carbono en el líquido depende de la presión y la temperatura de la lata de refresco, y también de agitar la lata de refresco que introduce burbujas que permanecen ocultas hasta que se abre la lata antes de que burbujee.
Por lo tanto, dado que la presión en la lata de refresco permanece constante, elevar la temperatura, agitar la lata de refresco o congelar el refresco, lo que aumenta la cantidad de dióxido de carbono en la porción líquida, hará que el refresco forme espuma y se derrame.
Explanation:
in which instrument of the following the washer works works as a valve? a)syringe b)hydraulic garage lift c)air pump d)watre pump
Answer:
A
Explanation:
The instrument in which the washer works as a valve is A ; syringe
Each instrument listed have a washer and a valve, but of all the instruments listed above the instrument that its washer works also as a valve is the syringe.
A syringe is composed of a thin tube and a thinner hollow needle attached to the end of the thin tube. the needle is used and take in liquids and also expel liquids from the syringe ( i.e. washer and valve )
hence the instrument that its washer also functions as a valve is the syringe.
learn more about syringe : https://brainly.com/question/24283167
Some consumers, like lions, do not eat plants or any other producers. They only eat other animals. How do lions obtain the carbon they need?
whoever gets it first gets to be Brainlist
Answer:
BHAI SECOND OPTION HOGA
Answer:b
Explanation:
Compare the reactivity of Sodium and Potassium when reacting with Chlorine.
Explanation:
Both sodium and potassium belong to the same group. They both have only one electon in their outermost shell. But they belong to different periods. Sodium has 3 shells while potassium has 5. As the distance between the valence electron and the nucleus is more in potassium. It experience lesser pull by the nucleus and so can give away the valence electron very easily as compared to sodium which experience a greater pull from the nucleus. Thus potassium is more reactive. Reactivity increases on moving down the group.
Answer:
Sodium and potassium belongs to same group . Both has 1 electron to donate but sodium is less reactive because nuclear attraction makes it little bit difficult to loose electron as compared to potassium in which nuclear attraction becomes unable to pull the electrons towards itself . Hence we easily remove electron moreover due to screening effect also takes place .
what does high pressure systems usually cause?
What was the main aim of Cavendish’s work?
Answer:
The Cavendish experiment, performed in 1797–1798 by English scientist Henry Cavendish, was the first experiment to measure the force of gravity between masses in the laboratory and the first to yield accurate values for the gravitational constant
Explanation:
I think that's correct
can u plz solve it n send the answer
1. Cl2 + H2O → HOCl + HCl
2. Tooth decay starts when when the pH of the mouth is lower than 5.5. Tooth enamel is made up of calcium phosphate and it is one of the hardest substances of the body. But it is corroded when the pH is less than 5.5. The bacteria of our mouth produce acids by degradation of sugar and food particles remaining in our mouth after eating food.
3. Fluorine salts are added in toothpaste to protect our teeth from tooth decay. Fluorine salts are mildly basic, so they neutrelise the acid in our mouth that leads to tooth decay.
4. Tincture of iodine is iodine, pottasium iodide and sodium iodide dissolved in ethanol. Iodine acts in an antiseptic manner by destroying microbial proteins and DNA.
5. Tincture of iodine is clear and reddish brown liquid.
what protects the cells of plants
Explanation:
Plant cells have several structures not found in other eukaryotes. In particular, organelles called chloroplasts allow plants to capture the energy of the Sun in energy-rich molecules; cell walls allow plants to have rigid structures as varied as wood trunks and supple leaves; and vacuoles allow plant cells to change size.
The cell wall is located outside the cell membrane. It consists mainly of cellulose and may also contain lignin , which makes it more rigid. The cell wall shapes, supports, and protects the cell. It prevents the cell from absorbing too much water and bursting.
how many Molecules and atoms of the product 2H2O+ O2
Answer:
A water molecule is composed of two hydrogen atom and one oxygen atom but you can't simply take two hydrogen atom stick them onto an oxygen atom
Mole concept
Calculate the number of iodine atoms in 4.50g of iodine gas
Answer:
0.017g/mol
Explanation:
according to the mole concept to calculate the number of moles of a substance you use the formula
number of moles= mass/molecular mass
=4.5g/254g/mole
=0.017moles
I hope this helps and sorry if it's wrong
Please hurry this is due tomorrow morning
A student is studying the ways different elements are similar to one another. Diagrams of
atoms from four different elements are shown below.
Which two atoms are of elements in the same group in the periodic table?
F Atom 1 and Atom 2
G Atom 1 and Atom 4
H Atom 2 and Atom 3
J Atom 3 and Atom 4
what is depletion??
good morning have A crazy day
Explanation:
reduction in the number or quantity of something.
"the depletion of the ozone layer" is called depletion
A science student observes that a dissolvable antacid tablet acts faster in relieving stomach pain when taken with warm water than when taken with water at room temperature. Based on the observation, suggest a potential problem that can be studied. Also, list the dependent, independent, and controlled variables that can exist in such an investigation.
Answer:
We know that an antacid is a base that can neutralize the stomach acid when ingested. The student observed that a soluble antacid tablet reacted faster in relieving pain due to the excess acid secreted in the stomach. So, the problem that can be studied is the effect of temperature on the rate of neutralization of stomach acid by the antacid. The independent variable is the one the student is going to vary that is the temperature. The dependent variable is the rate of reaction or the time taken for an antacid tablet to neutralize the acid present in stomach. The controlled variable is the tablet taken, that is the student should use a specific antacid tablet to ensure that the rate of reaction or the time taken for the antacid tablet to neutralize the acid present in stomach is not affected by the chemical composition of tablet.
Explanation:
Hope u understood.
2.5 kilogram into gram
Answer:
2500grams
hope this helps
Answer: 2500 gram
Explanation:
Concept:
Here, we need to know the idea of unit conversion.
Unit conversion is the conversion between different units of measurement for the same quantity, typically through multiplicative conversion factors.
1 kg = 1000 g
Solve:
1kg = 1000g
2.5kg = 2.5 × 1000 = 2500g
Hope this helps!! :)
Please let me know if you have any questions
