1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
skelet666 [1.2K]
3 years ago
9

Alessandro has committed to riding his bike to and from school when the weather is good. All week, he rides to school without an

y problems. But on Friday, he remembers that he must bring home equipment for a science experiment that is too big to carry on a bike. What did Alessandro forget to do before making his lifestyle change
Chemistry
1 answer:
Bess [88]3 years ago
6 0
He forgot to bring his equipment home
You might be interested in
Ter the symbol for the isotope used in blood flow analyses.
blondinia [14]

Answer:

The symbol of isotopes used for blood flow analysis is \begin{array}{c}{141} \\ {58}\end{array} C e.

<u>Explanation: </u>

  • Isotopes are the substances that exhibit the same atomic number but has a different mass number of an element.
  • The atomic number explains the number of protons present in the element and mass number explains the number of neutrons available in the element.
  • For blood flow analysis, the isotope element is cerium-141 and it is used in the chemical examination of blood flow particles.
  • Symbol used for this isotope is \begin{array}{c}{141} \\ {58}\end{array} C e, where 141 indicates the amount of mass present and 58 indicates the proton number and 83 indicates neutron number present in that element.
  • The amount of mass in an atom is calculated by the sum of protons and neutrons present in it. Thus mass of isotope is 141 obtained by the sum of 58 protons and 83 neutrons present in that isotope.
8 0
4 years ago
The decomposition reaction of A to B is a first-order reaction with a half-life of 2.42×103 seconds: A → 2B If the initial conce
kipiarov [429]

Answer:

t=23.5min

Explanation:

Hello,

In this case, since the rate equation turns out as shown below due to the first-order kinetics:

\frac{dC_A}{dt}=-kC_A

Its integration results:

\int\limits^{C_A}_{C_A^0} { \frac{dC_A}{C_A}} \,=-k\int\limits^t_0 {} \, dt\\ln(\frac{C_A}{C_A^0})=-kt

However, the rate constant is computed by considering the given half-life time as follows:

k=\frac{ln(2)}{t_{1/2}}=\frac{ln(2)}{2.42x10^3s}=2.86x10^{-4}s^{-1}

In such a way, the required time in minutes to diminish the concentration by 66.8% of the initial turns out:

C_A=0.668C_A^0

ln(\frac{0.668C_A^0}{C_A^0})=-kt

t=\frac{-ln(0.668)}{2.86x10^{-4}s^1}=1408.3s*\frac{1min}{60s} \\t=23.5min

Best regards.

3 0
3 years ago
Using the periodic table to locate each element, write the electron configuration of(c) Re.
Aleksandr [31]

Rhenium is a chemical element with the symbol Re and atomic number 75. The electron configuration of Re is [Xe] 6s^{2} 4f^{14} 5d^{5}.

<h3>How to write an electronic configuration?</h3>

1. Identify the given element and its atomic number from the periodic table.

2. Write the electron configuration by the energy level and the type of orbital first, then the number of electrons present in the orbital as superscript.

The easiest way to write the electronic configuration for any element is by   using a diagonal rule for electron filling order in the different subshells according to the Aufbau principle.

The 3 rules for writing the electron configuration in the orbital box diagram are – the Aufbau rule, the Pauli-exclusion rule, and Hund's Rule.

To learn more about electronic configuration, refer

https://brainly.ph/question/73419

#SPJ4

5 0
2 years ago
To determine the concentration of chloride ion (Cl-) in a 100 mL sample of ground water, a chemist adds a large enough volume of
Orlov [11]

Answer:

[Cl^-]=232.3\frac{mgCl^-}{L}

Explanation:

Hello,

In this case, we can represent the chemical reaction as:

Cl^-(aq)+AgNO_3(aq)\rightarrow AgCl(s)+NO_3^-(aq)

In such a way, since the mass of the obtained silver chloride is 93.9 mg, we can compute the chloride ions in the ground water by using the following stoichiometric procedure whereas the molar mass of chloride ions and silver chloride are 35.45 g/mol and 143.32 g/mol respectively:

m_{Cl^-}=93.3mgAgCl*\frac{1mmolAgCl}{143.32mgAgCl}*\frac{1mmolCl^-}{1mmolAgCl} *\frac{35.45mgCl^-}{1mmolCl^-} =23.23mgCl^-

Finally, for the given volume of water in liters (0.100L), we compute the required concentration:

[Cl^-]=\frac{23.2mgCl^-}{0.100L}\\

[Cl^-]=232.3\frac{mgCl^-}{L}

Best regards.

5 0
4 years ago
2. Zn + HCI. ZnCl2 + H2<br><br>what reaction is this ​
steposvetlana [31]

Answer: Type of Chemical Reaction: For this reaction we have a combination reaction. Balancing Strategies: When we add zinc to hydrochloric acid we end up with zinc chloride, a salt, and hydrogen gas. This reaction is actually a good way to make hydrogen gas in the lab.

5 0
3 years ago
Other questions:
  • if 100. mL of 0.800 M Na2SO4 is added to 200. mL of 1.20 M NaCl, what is the concentration of Na+ ions in the final solution? As
    7·1 answer
  • Prokaryotic cells have a nucleus true or false quick pls
    6·1 answer
  • What kind of mixture is a solution? A suspension? A colloid?
    12·2 answers
  • What evidence is there to suggest that the Earth is composed of tectonic plates?
    12·1 answer
  • A solution is prepared by mixing 50.0 mL of ethanol with 300.0 mL of water. What is the volume percent of ethanol in this soluti
    14·1 answer
  • Find the volume of 10g of gasoline if it has a density of 0.7g/mL
    9·1 answer
  • According to the law of mass action,what must be equal at equilibrium?
    14·1 answer
  • The two balanced equations (1) and (2) are for reactions in which gaseous carbon dioxide is produced from the combustion of (1)
    9·1 answer
  • if five gases contained in a cylinder each exert a pressure of 1.0 atm what is the total pressure exerted by the gases
    15·2 answers
  • Please answer the question
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!