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
Nuetrik [128]
3 years ago
6

The original amount of radioactive substance is 10 grams. After several years, 2.5 gtams of the substance is remaining. How many

half-lives havr passed since the mass of the subtance was 10 grams?
Chemistry
1 answer:
nirvana33 [79]3 years ago
8 0
10/2=5 (one half life)
5/2=2.5(two half lives)
You might be interested in
Name any <br>three kinds of mixtures with example​
sleet_krkn [62]

Answer:

Here are a few more examples:

Smoke and fog (Smog)

Dirt and water (Mud)

Sand, water and gravel (Cement)

Water and salt (Sea water)

Potassium nitrate, sulfur, and carbon (Gunpowder)

Oxygen and water (Sea foam)

Petroleum, hydrocarbons, and fuel additives (Gasoline)

Heterogeneous mixtures possess different properties and compositions in various parts i.e. the properties are not uniform throughout the mixture.

Examples of Heterogeneous mixtures – air, oil, and water, etc.

Examples of Homogeneous mixtures – alloys, salt, and water, alcohol in water, etc.

Explanation:

8 0
3 years ago
Read 2 more answers
Explain why world food shortages could be reduced by growing more algae.
Sonja [21]
One of the many awe-inspiring things about algae, Professor Greene explains, is that they can grow between ten and 100 times faster than land plants. In view of this speedy growth rate – combined with the fact they can thrive virtually anywhere in the right conditions – growing marine microalgae could provide a variety of solutions to some of the world’s most pressing problems.

Take, global warming. Algae sequesters CO2, as we have learned, but owing to the fact they grow faster than land plants, can cover wider areas and can be utilised in bioreactors, they can actually absorb CO2 more effectively than land plants. AI company Hypergiant Industries, for instance, say their algae bioreactor was 400 times more efficient at taking in CO2 than trees.

And it’s not just their nutritional credentials which could solve humanity’s looming food crisis, but how they are produced. Marine microalgae grow in seawater, which means they do not rely on arable land or freshwater, both of which are in limited supply. Professor Greene believes the use of these organisms could therefore release almost three million km2 of cropland for reforestation, and also conserve one fifth of global freshwater
8 0
2 years ago
Write the net ionic equation:. . A solution of diamminesilver(I) chloride is treated with dilute nitric acid
zimovet [89]
<span> Ag(NH3)2Cl + 3HNO3 = AgNO3 +2NH4NO3 + HCl </span>
<span>or
 Ag(NH3)2Cl + HNO3 = Ag(NH3)2NO3 + HCl  this the complete balanced equation
now remove spectator ions to get net ionic equation
so 
</span>
<span> 2H+ + 2NO3- + [Ag(NH3)2]+ Cl- -> AgCl + 2NH4+ + 2NO3-  2NO3-  2H+  [Ag(NH3)2]+ + Cl- -> AgCl + 2NH4+
</span>hope it helps
5 0
3 years ago
Read 2 more answers
A scuba tank has a pressure of 195 KPa at a temperature of 10 °C. The volume of the tank is 350 L. How many grams of air is in t
marissa [1.9K]

The mass of air in the scuba tank is 841.614 g.

Using the ideal gas equation;

PV=nRT

P = pressure of the gas = 195 kPa

V = volume of the gas =  350 L

n = Number of moles of the gas = ??

R = molar gas constant = R = 8.314 J K-1 mol-1

T = temperature of the gas =  10 °C or 283 K

n = PV/RT

n = 195 * 350/8.314 * 283

n = 68250/2352.862

n = 29.00 moles

Number of moles = mass/molar mass

mass of air = Number of moles * molar mass

mass of air = 29.00 moles * 29g/mol

Mass of air = 841.614 g

Learn more: brainly.com/question/4147359

5 0
2 years ago
A biochemist carefully measures the molarity of magnesium ion in of cell growth medium to be . Unfortunately, a careless graduat
denis23 [38]

Answer:

760 uM

Explanation:

<em>A biochemist carefully measures the molarity of magnesium ion in 47, mL of cell growth medium to be 97 uM. Unfortunately, a careless graduate student forgets to cover the container of growth medium and a substantial amount of the solvent evaporates. The volume of the cell growth medium falls to 6.0 mL. Calculate the new molarity of magnesium ion in the cell growth medium Be sure your answer has the correct number of significant digits.</em>

The problem here is that the amount of magnesium ion remains the same irrespective of the volume.

Amount of magnesium in the growth medium = <em>molarity x volume</em>

    = 97 x 10^{-6} x 47 x 10^{-3} = 4.559 x 10^{-6}

Then, the volume reduced to 6.0 mL, the new molarity becomes;

<em>molarity = mole/volume </em>

       = 4.559 x 10^{-6}/6 x 10^{-3} = 7.598333 x 10^{-4} M = 759.83333 uM

To the correct number of significant digits = 760 uM

6 0
3 years ago
Other questions:
  • On a molar basis, which is a more effective bleaching agent- kbro3 or naocl?
    7·1 answer
  • If an atom contains 1 electron and 1 proton will it carry any charge or not?
    7·1 answer
  • 1 Point
    14·1 answer
  • Which of the following is NOT true regarding Rutherford's Gold Foil experiment?
    9·1 answer
  • which of the following does not represent a molecular compound? A)CS2 B)Bal2 C)N2O4 D)PCI3
    13·2 answers
  • Write the balanced NET ionic equation for the reaction when AlCl 3 NaOH are mixed in aqueous solution. If no reaction occurs, wr
    9·1 answer
  • Which is the correct choice
    5·1 answer
  • PLEASE HELP MEEE I WILL MARK BRAINLIST FOR THIS ITS SUPER SIMPLE....BUT U MUST TYPE EVERYTHING needed ASAP
    12·1 answer
  • Using spdf notation, what is the electron configuration for a neutral atom of beryllium
    9·1 answer
  • According to kinetic molecular theory, which of the following would not be considered an ideal gas
    7·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!