Answer:
B
Explanation:
I did the question before and got it right.
Barium – 122 has a half-life of 2 minutes. Suppose you obtain a sample weighing 10.0 g and it takes 10 minutes to set up an experiment. How many grams of Barium – 122 will remain at the point when you begin the experiment
Answer:
0.3125 g
Explanation:
Given data:
Half life of barium-122 = 2 min
Mass of sample = 10.0 g
Mass of barium remain after 10 min = ?
Solution:
Number of half lives = Time elapsed / half life
Number of half lives = 10 min/ 2 min
Number of half lives = 5
At time zero = 10 g
At 1st half life = 10 g/2 = 5 g
At 2nd half life = 5 g/2 = 2.5 g
At 3rd half life = 2.5 g/2 = 1.25 g
At 4th half life = 1.25 g/2 = 0.625 g
At 5th half life = 0.625 g/2 = 0.3125 g
The reaction between HCl and KOH results in an increase in temperature in the solution. Select the correct statement from the list below.
a) this is an endothermic reaction
b) this is a phase change reaction
c) this is a vaporization reaction
d) this is an exothermic reaction
Answer:
d) this is an exothermic reaction.
Explanation:
The reaction between HCl and KOH results in an increase in temperature in the solution. Select the correct statement from the list below.
a) this is an endothermic reaction . NO. This would cause a decrease in the temperature of the solution.
b) this is a phase change reaction . NO. All the species remain in the aqueous phase.
c) this is a vaporization reaction . NO. All the species remain in the aqueous phase.
d) this is an exothermic reaction. YES. The reaction releases heat, so it is exothermic.
What best describes the location of an atom's electrons?
Predict which of the following metals reacts with hydrochloric acid.
Check all that apply.
-Sn
-Hg
-Cr
-Ni
Answer:
Pb, Cr, Fe
Explanation:
The metals that can react with hydrochloric acid are; Sn, Cr and Ni.
The electrochemical series shows the reactivity of elements. An element can only replace another element in solution when that element is higher in the electrochemical series.
The metals that can replace hydrogen in a solution of hydrochloric acid must be metals that are above hydrogen in the electrochemical series. These metals are; Sn, Cr and Ni. Hg is a noble metal hence it does not replace hydrogen in an acid solution.
Learn more: https://brainly.com/question/25249351
the moon lost its volcanic __ beacuse of its weak gravity
Answer:
Explanation:
the moon is still volcanic
1. Marisa determined the melting point of a substance to be 24.5C. Find the percent error of her measurement if the actual melting point is 31.2C.
Answer:
[tex]\%\ Error = 21.5\%[/tex]
Explanation:
Given
[tex]Measured = 24.5[/tex]
[tex]Actual = 31.2[/tex]
Required
Determine the percentage error
First, we need to determine the difference in the measurement
[tex]Difference = |Actual - Measured|[/tex]
[tex]Difference = |31.2 - 24.5|[/tex]
[tex]Difference = |6.7|[/tex]
[tex]Difference = 6.7[/tex]
The percentage error is calculated as thus:
[tex]\%\ Error = \frac{Difference * 100\%}{Actual}[/tex]
[tex]\%\ Error = \frac{6.7 * 100\%}{31.2}[/tex]
[tex]\%\ Error = \frac{670\%}{31.2}[/tex]
[tex]\%\ Error = 21.4743589744\%[/tex]
[tex]\%\ Error = 21.5\%[/tex] approximated
What are graphs? Give an example of a graph that would be useful to you in your everyday life
Answer:
A graph can be very handy in collecting data and storing it in one place. A graph can be a very effective tool in presenting visual information rather swiftly. Hope this helps! I am learning about graphs in my course!
Explanation:
Answer:
graph) a diagram showing the relation between variable quantities, typically of two variables, each measured along one of a pair of axes at right angles.
Explanation:
Graphing is used daily. From stockbrokers to performance evaluation in companies. All use them to boost sales and meet deadlines. Even simple calculations can be assessed better by using a graph.
(let me know if this helps?)
Look at the image HOH. What does this image represent?
Answer:
Formation of covalent bond structures. The image is essentially a Lewis dot structure.
The image of HOH has depicted the covalent bond formation in water. Thus, option B is correct.
The image has been the Lewis structure of the water molecule. It has been consisted of two hydrogen atoms bonded to oxygen molecules.
The oxygen has a presence of 4 dots that have been the representation of the valence electrons. Thus, oxygen has been consisted of 2 lone pairs.
The water molecule has the presence of shared electrons between hydrogen and oxygen. The bond formed by the sharing of electrons has been covalent.
Thus, the image of HOH has been the representation of the formation of covalent bonds in water. Thus, option B is correct.
For more information about Lewis structure, refer to the link:
https://brainly.com/question/4144781
A 57.07 g sample of a substance is initially at 24.3°C. After absorbing of 2911 J of heat, the temperature of the substance is 116.9 CWhat is the specific heat (SH) of the substance?
Answer:
Approximately [tex]0.551\; \rm J\cdot kg^{-1} \cdot \left(^\circ\! C \right)^{-1}[/tex].
Explanation:
The specific heat of a material is the amount of energy required to increase unit mass (one gram) of this material by unit temperature (one degree Celsius.)
Calculate the increase in the temperature of this sample:
[tex]\Delta T = (116.9 - 24.3)\; \rm ^\circ\! C= 92.6\; \rm ^\circ\! C[/tex].
The energy that this sample absorbed should be proportional the increase in its temperature (assuming that no phase change is involved.)
It took [tex]2911\; \rm J[/tex] of energy to raise the temperature of this sample by [tex]\Delta T = 92.6\; \rm ^\circ\! C[/tex]. Therefore, raising the temperature of this sample by [tex]1\; \rm ^\circ\! C[/tex] (unit temperature) would take only [tex]\displaystyle \frac{1}{92.6}[/tex] as much energy. That corresponds to approximately [tex]31.436\; \rm J[/tex] of energy.
On the other hand, the energy required to raise the temperature of this material by [tex]1\; \rm ^\circ\! C[/tex] is proportional to the mass of the sample (also assuming no phase change.)
It took approximately [tex]31.436\; \rm J[/tex] of energy to raise the temperature of [tex]57.07\; \rm g[/tex] of this material by [tex]1\; \rm ^\circ C[/tex]. Therefore, it would take only [tex]\displaystyle \frac{1}{57.07}[/tex] as much energy to raise the temperature of [tex]1\; \rm g[/tex] (unit mass) of this material by [tex]1\; \rm ^\circ \! C\![/tex]. That corresponds to approximately [tex]0.551\; \rm J[/tex] of energy.
In other words, it takes approximately [tex]0.551\; \rm J[/tex] to raise [tex]1\; \rm g[/tex] (unit mass) of this material by [tex]1\; \rm ^\circ \! C[/tex]. Therefore, by definition, the specific heat of this material would be approximately [tex]0.551\; \rm J\cdot kg^{-1} \cdot \left(^\circ\! C \right)^{-1}[/tex].
PLEASE HELP AND FAST!!!
how do you write 652870000 in scientific notations
9
6.5287×10Explanation:This is the correct answerPlease help!!
This is a big part of my grade -----
Will make you brainliest******
Explanation:
U need to draw the graph first and make a line at 17 pennies, where the line of 17 pennies and your graph meet is the mass of it(at y axis)
Which of these would be classified as a chemical property that could be measured quantitatively?
Volume
Flammability
рн
Solubility
Answer:
рн
Explanation:
From the given choices, pH is the only chemical property that can be measured quantitatively.
A chemical property is one that tells us about what a substance can do as regards to whether or not the substance reacts with other substances.
Examples are flammability, rusting of iron, precipitation, decomposition of water e.t.c
pH is the degree of acidity or alkanility of a solution. It is usually determined quantitatively using a pH scaleThe scale is graduated from 1 to 14 1 to 7 is for acids7 is for neutral compounds7-14 is for alkalines.Hereditary information is passed on from:
O nucleus to nucleus
O cell to cell
O cell to nucleus
O nucleus to cell
Answer:
D - Nucleus to Cell
Explanation:
Hope it helps!!
:D
How many grams of H3PO4 would be needed to produce 25.0 grams of H2O?
Answer:
653 gH³PO⁴
Explanation:
We'll first write the chemical equation for this reaction:
P
4
O
10
(
s
)
+
6
H
2
O
(
l
)
→
4
H
3
PO
4
(
a
q
)
Let's now find the relative number of moles of phosphoric acid (
H
3
PO
4
) using the coefficients of the equation, and the fact that
10.0
mol H
2
O
react:
10.0
mol H
2
O
(
4
l
mol H
3
PO
4
6
mol H
2
O
)
=
6.67
mol H
3
PO
4
Now, using the molar mass of
H
3
PO
4
(calculated to be
98.00
g/mol
), let's find the theoretical mass of phosphoric acid produced:
6.67
l
mol H
3
PO
4
(
98.00
l
g H
3
PO
4
1
mol H
3
PO
4
)
=
653
mol H
3
PO
4
Thus, if the reaction goes to completion, there will be a yield of
653
grams of phosphoric acid
Thank me later
Mark me as brainliest please for my answer
What is the mass/volume percent of a solution with 7.5g of Na2CO3 dissolved in 20.0 g of water?
9.3 %
27%
7.5%
Answer:
7.5%
Explanation:
I just know it's that
The radius of Pt atom in an fcc structure is 0.1386 nm. Pt has atomic mass of 195.09 g/mol. Calculate the density of this fcc structure. The Avogadro’s number NAis 6.022 x 1023 per mole
Answer:
21.51g/cm³
Explanation:
To answer this question we need to know that, in 1 unit FCC cell:
Edge length = √8 * R
Volume = 8√8 * R³
And there are 4 atoms per unit cell
The mass of the 4 atoms of the cell, in grams, is:
4 atom * (1mol / 6.022x10²³atom) * (195.09g / mol) = 1.2958x10⁻²¹g
Volume in cm³:
0.1386nm * (1x10⁻⁷cm / 1nm) = 1.386x10⁻⁸cm
Volume = 8√8 * (1.386x10⁻⁸cm)³
Volume = 6.02455x10⁻²³cm³
And density, the ratio of mass and volume, is:
1.2958x10⁻²¹g / 6.02455x10⁻²³cm³ =
21.51g/cm³
What is the force of a 10 kg bowling ball with an acceleration of 8 m/s/s?
0 18 N
0 80 N
O 2N
The answer is 80N
(hope this helps you!!!)
Calculate the density of the aluminum cylinder with a diameter 0f 1.3 cm weighing 18 grams. Height of the cylinder is 5.2 Cm. Find percent error (Actual density of Aluminum is 2.7 g/cm3). (Formula for volume of cylinder is πr2h)
Answer:
Percent error = 3.7%
Explanation:
Given data:
Density of Al cylinder = ?
Weight of cylinder = 18 g
Diameter = 1.3 cm
Height = 5.2 cm
Actual density of Al = 2.7 g/cm³
Percent error = ?
Solution:
First of all we will calculate the volume of cylinder through given formula.
V = πr²h
r = diameter /2
V = 22/7 × (0.65 cm)²× 5.2 cm
V = 22/7 × 0.4225cm²× 5.2 cm
V = 6.89 cm³
Now we will calculate the density.
d = m/v
d = 18 g/ 6.89 cm³
d = 2.6 g/cm³
Percent error:
Percent error = measured value - actual value /actual value × 100
Percent error = 2.6g/cm³ - 2.7g/cm³ /2.7g/cm³ × 100
Percent error = 3.7%
Negative sign shows that measured or experimental value is less than actual value.
Aqueous solutions of calcium chloride and sodium hydroxide are mixed together, forming solid calcium hydroxide and aqueous sodium chloride. Write the balanced chemical equation for the reaction. Phases are optional.
Answer:
CaCl₂ (aq) + 2NaOH (aq) —> Ca(OH)₂ (s) + 2NaCl (aq)
Explanation:
The equation for the reaction is given below:
CaCl₂ (aq) + NaOH (aq) —> Ca(OH)₂ (s) + NaCl (aq)
The above equation can be balance by as follow:
CaCl₂ (aq) + NaOH (aq) —> Ca(OH)₂ (s) + NaCl (aq)
There are 2 atoms of Cl on the left side and 1 atom on the right side. It can be balance by putting 2 in front NaCl as shown below:
CaCl₂ (aq) + NaOH (aq) —> Ca(OH)₂ (s) + 2NaCl (aq)
There are 2 atoms of Na on the right side and 1 atom on the left side. It can be balance by putting 2 in front of NaOH as shown below:
CaCl₂ (aq) + 2NaOH (aq) —> Ca(OH)₂ (s) + 2NaCl (aq)
Now, the equation is balanced.
why is steel a mixture
Answer:
Steel is a mixture because iron does not mix with the carbon and the other components.
Answer:
Steel is a mixture because it does not have a set chemical compound formula. It's a mixture of iron and carbon fused together with other metals or nonmetals to create a mixture.
Explanation:
Steel is an alloy , a solid solution
Steel is a homogenous mixture. It is not a pure substance because it is made form more than one component.
Answer each of the following questions with increases, decreases, or does not change.
a) If the intermolecular forces in a liquid increase, the normal boiling point of the liquid increases .
b) If the intermolecular forces in a liquid increase, the vapor pressure of the liquid does not change .
c) If the surface area of a liquid increases, the vapor pressure increases .
d) If the temperature of a liquid decreases, the equilibrium vapor pressure increases .
Drag and drop your selection from the following list to complete the answer:
does not change decreases increases
Answer:
1) Increases
2) decreases
3) increases
4) decreases
Explanation:
When the intermolecular forces in a liquid increases, the greater vapour pressure of the liquid decreases accordingly.
Since the vapour pressure is proportional to temperature, as temperature increases, the vapour pressure increases alongside.
As intermolecular forces increases, the boiling point increases accordingly since more energy is required to break intermolecular bonds.
Lastly, the greater the surface area, tell greater the vapour pressure since more liquid surface area is now available.
The process of reviewing information using an investigator is knowledge, training, experience, and expertise is what type of reasoning?
Answer:
Inductive reasoning
Explanation:
Inductive reasoning is based on making broad generalizations from specific observations. We draw conclusions from the data we have. This is the opposite of deductive reasoning, which starts with a general statement and aims to reach a specific conclusion.
Based on this, we can conclude that, if an investigator uses their knowledge, training, experience, and expertise to reach a conclusion, they are using inductive reasoning.
What is the correct systematic name for ICl5?
Answer:
iodine pentachloride
Explanation:
Identifying the particles of an atom
Answer:
6 protons 8 neutrons 5 electrons
Explanation:
protons are blue neutrons are red electrons are green
Which of the following contribute(s) to most of the mass of an atom? Question 5 options: A) Neutrons only B) Protons and electrons C) Protons and neutrons D) Protons only
Answer:
C
Explanation:
Hope this helps :)
How many moles are in 141.16 grams of F?
Use two digits past the decimal for all values
Answer: 2681.81
Explanation:
Which element is more reactive?
A) Flourine B) Oxygen C)Cabron D)Boron
Match the following terms and definitions.
1. major ecological grouping of plants and animals
food chain
biome
environmental factor
decomposers
2. bacteria and fungi that break down dead matter
a state of change in which the end result is equal or
3.
balanced
the basic relationships that show how a community of plants,
animals, and bacteria live and grow and how these living
4. things are dependent on each other as well as the Sun, soil,
and other nonliving parts of their environment; a cycle of
relationships
line of plants and animals that shows the order in which
5.
organisms are eaten
a condition or conditions of the nonliving surroundings, such
6.
as light, temperature, water, and so on
ecosystem
dynamic equilibrium
Answer:
major ecological grouping of plants and animals
food chain
*biome*
bacteria and fungi that break down dead matter
*decomposers*
a state of change in which the end result is equal or
balanced
*dynamic equilibrium*
the basic relationships that show how a community of plants,
animals, and bacteria live and grow and how these living
*ecosystem*
things are dependent on each other as well as the Sun, soil,
and other nonliving parts of their environment; a cycle of
relationships
line of plants and animals that shows the order in which
*Food chain*
organisms are eaten
a condition or conditions of the nonliving surroundings, such
*environmental factor*
Explanation:
g Calculate the mass percent of sodium bicarbonate in the solution that has 7.00 g of solution and 0.052 Kg of water.
Answer:
11.86%
Explanation:
First, we convert both solvent and solute to the same unit, say, kg. We have.
Mass of Sodium Bicarbonate = 7g = 7/1000 kg = 0.007 kg
Mass of water = 0.052 kg.
Formula for the mass percent is
% of sodium bicarbonate = [(mass of sodium bicarbonate) / (mass of total solution) * 100%]
Total mass of solution = 0.007 + 0.052 Total mass of solution = 0.059
% of sodium bicarbonate = 0.007 / 0.059 * 100%
% of sodium bicarbonate = 11.86%
Therefore, the mass percent of sodium bicarbonate I'm the solution is 11.86%