Write an informal definition of half-life.

Answers

Answer 1

the time required for the activity of a substance taken into the body to lose one half its initial effectiveness. Informal. a brief period during which something flourishes before dying out.

hope this helps ^^


Related Questions

If 2.5 grams of calcium bromide reacted with excess lithium oxide, how many grams of bromide product would be formed?

Answers

Answer: 2.17 g of  bromide product would be formed

Explanation:

The reaction of calcium bromide with lithium oxide will be:

[tex]CaBr_2+Li_2O\rightarrow 2LiBr+CaO[/tex]

To calculate the moles :

[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]    

[tex]\text{Moles of calcium bromide}=\frac{2.5g}{199.9g/mol}=0.0125moles[/tex]

As lithium oxide is in excess, calcium bromide is the limiting reagent.

According to stoichiometry :

1 mole of [tex]CaBr_2[/tex] produce = 2 moles of [tex]LiBr[/tex]

Thus 0.0125 moles of [tex]CaBr_2[/tex] will require=[tex]\frac{2}{1}\times 0.0125=0.025moles[/tex]  of [tex]NH_3[/tex]

Mass of [tex]LiBr=moles\times {\text {Molar mass}}=0.025moles\times 86.8g/mol=2.17g[/tex]

Thus 2.17 g of  bromide product would be formed

Convert 4.5 x 10-3 to standard Notation
Posted today at 6:30 am
1
=

Answers

Answer:

0.0045

Explanation:

Scientific notation is the way to express the large value in short form.

The number in scientific notation have two parts.

The digits (decimal point will place after first digit)

× 10 ( the power which put the decimal point where it should be)

for example 4.5×10⁻³

In standard notation

4.5 / 10³

0.0045

The expanded notation is standard notation of writing the numerical values which is normal way. The numbers are written as they are, without the power of 10.

which is more reactive oxygen or hydrogen? explain why?

Answers

Answer:

Explanation:

Which is more reactive hydrogen or oxygen?

Hydrogen is not particularly reactive. For example, just mixing hydrogen and oxygen gas will not cause a reaction at room temperature, but many metal elements oxidize at least on the surface in air. ... It is combustible because oxygen wants electrons and takes them from hydrogen to form water.

Given the following reaction, how many molecules of H2O will be formed from 200.0g of NaOH?
2 NaOH + H2SO4 -> 2 H2O + Na2SO4

Answers

Answer:

30.11×10²³ molecules

Explanation:

Given data:

Mass of NaOH = 200.0 g

Number of molecules of water formed = ?

Solution:

Chemical equation:

2NaOH + H₂SO₄      →     2H₂O + Na₂SO₄

Number of moles of NaOH:

Number of moles = mass/molar mass

Number of moles = 200 g/ 40 g/mol

Number of moles = 5 mol

Now we will compare the moles of NaOH and H₂O.

                      NaOH         :        H₂O

                          2             :          2

                         5              :            5

Number of molecules of water:

1 mole contain 6.022×10²³ molecules

5 mol × 6.022×10²³ molecules / 1mol

30.11×10²³ molecules

Which of the following is the best hypothesis?
*
A. I think the plants given acid will grow taller
B. The plants given acid will be smaller than the plants given only water
C.The plants given water will be better
D.I believe the plants given acid will be smaller

Answers

Answer:

b

Explanation:

i think it is b

explain with example the combination and decomposition reaction.​

Answers

Answer:

Decomposition reactions require an input of some form of energy. For example, under the influence of an electric field, water breaks down to give hydrogen and oxygen. In the presence of sunlight, hydrogen peroxide decomposes into oxygen and water.

In a population of wheat,
variation in the height of
the wheat decreases
over time so that short
wheat plants survive
more than other heights.

Answers

Right push is good man

Which kind of worm has a closed circulatory system?

a planarian
a fluke
a pinworm
an earthworm

Answers

An earthworm has a closed circulatory system.

The earthworm has a closed circulatory system. An earthworm circulates blood exclusively through vessels. There are three main vessels that supply the blood to organs within the earthworm.

As important as they are alive for distributing nutrients and organisms and decomposing matter, worms are also very important in the food chain. They provide a crucial protein-rich source of food for other important species like birds, hedgehogs and frogs.

They may live up to eight years, though one to two is more likely. Full size for an earthworm varies among species, ranging from less than half an inch long to nearly 10 feet.

Learn more about earthworm here:- https://brainly.com/question/13938105

#SPJ1

100 pts
HELP!!!!!!!!
Between steps 2 and 3, the chemical energy in the coal is converted to
electrical energy

mechanical energy

transitional energy

heat energy

Answers

Answer:

It Is Transitional Energy.

Explanation: I Took The Quiz And Got It Wrong. It Showed That Transitional Energy Was The Correct Answer.

Answer:

heat energy

Explanation:

Which material has carbon atoms interspersed with iron atoms in its molecular structure?
0 hematite
0malachite
0 bauxite
0 steel

Answers

Answer:

steel should be correct

Balance this equation by filling in the missing coefficient: 6 CO2 + 6 H2O + Sunlight = C6H12O6 + ?? O2
A. 1
B. 6
C. 12
D. 36

Answers

Given that,

The equation is : [tex]6CO_2+6H_2O+\text{sunlight}\rightarrow C_6H_{12}O_6+?O_2[/tex]

To find,

The missing coefficients.

Solution,

[tex]6CO_2+6H_2O+\text{sunlight}\rightarrow C_6H_{12}O_6+?O_2[/tex]

Let the value of ? is x.

It is the equation of photosynthesis.

In LHS,

Carbon atoms = 6

Hydrogen atom = 12

Oxygen atom = 18

In RHS,

Carbon atoms = 6

Hydrogen atom = 12

Oxygen atom = 6

If we make the equation as [tex]6CO_2+6H_2O+\text{sunlight}\rightarrow C_6H_{12}O_6+6O_2[/tex]

No the number of atoms in RHS = 6+ 12 = 18

It means if we take the value of ? as 6 the equation will be balanced.

Hence, the correct option is (B) "6".

Explain in a short sentence how you can tell if a reaction is a single replacement
reaction.

Answers

Explanation:

The reaction can be said to be a single replacement reaction if one substance in a chemical reaction is replacing another one.

For example:

            A + BC →  AC + B

In such reactions there is a replacement of a metallic ion in solution by a metal atom higher in the activity series than the metal in solution.

The relative positions of the two elements in the activity series provides the driving force for a single replacement reaction. If one element that is to replace another in a compound is more active, the reaction will occur. If it is less reactive, there will be no reaction.

An equation that shows only the chemical formulas without
anything to indicate relative amounts is called a ______.

Answers

Answer: skeleton equation

Explanation:

what type of heat transfer takes place when you come in contact with a snow flake on a cold day?

Answers

Answer:

Conduction

Explanation:

Conduction is how heat transfers through direct contact with objects that are touching. Any time that two objects or substances touch, the hotter object passes heat to the cooler object.

Answer:

Conduction

Explanation:

Conduction is how heat transfers through direct contact with objects that are touching. Any time that two objects or substances touch, the hotter object passes heat to the cooler object.

The movement of blood from your lungs to your heart is ______.

A. picks up nutrients, water, and waste materials

B. pulmonary circulation

C. the lungs, where it picks up oxygen again

D. capillaries

E. 5

F. systemic circulation

Answers

Answer:

B. Pulmonary Circulation

Explanation:

Pulmonary circulation moves blood between the heart and the lungs. It transports deoxygenated blood to the lungs to absorb oxygen and release carbon dioxide. The oxygenated blood then flows back to the heart.

After two alpha decays, Carbon-14 will become?

Answers

Answer:

Becomes Nitrogen-14

Explanation:

2. How are UVC rays different from UVA and UVB rays?
a. UVC rays are deflected by earth's atmosphere; UVA and UVB rays aren't
b. UVC rays can penetrate all the layers of your skin; UVA and UVB rays don't
c. UVC rays contain very little energy; UVA and UVB rays are very powerful
d. Sunblock can protect you against UVC rays, but not UVA and UVB rays

Answers

Answer: A.. for sure

Explanation:

what water has 97% of water

Answers

Answer:

ocean

Explanation:

because its easy

The answer would be Ocean

PLEEEASSEEEE HELPPPPP!!!!!Take some time to research a utility plant. If there is one in your area, you may even visit it.
Otherwise, look up a type of plant that produces energy - such as a nuclear power plant, a
hydroelectric plant, or a coal-burning plant. Find out what energy resources are brought into the
plant. Then find out what energy and what "waste" is produced by the plant. Describe how the
two Laws of Thermodynamics apply to what you find out in your research. Be thorough. You will
be using the information you gather to engage in a debate with your class about
thermodynamics.

Answers

Answer:

There are four laws of thermodynamics that define fundamental physical quantities (temperature, energy, and entropy) and that characterize thermodynamic systems at thermal equilibrium.

Explanation:

Subscripts in a molecular formula indicate how many of each type of ____ can be found

Answers

Answer:

Atoms

Explanation:

The molecular formula uses chemical symbols to indicate the types of atoms followed by subscripts to show the number of atoms of each type in the molecule. :)

How many elements, compounds and atoms are in CH3COOH

Answers

CH3COOH is called Acetic acid, also known as ethanoic acid and methane carboxylic acid, is a colorless liquid that has a strong and distinct pungent and sour smell. It has two carbon (C) atoms, four hydrogen (H) atoms and two oxygen (O) atoms. Because it has a carbon in its chemical formula, it is an organic compound

How many carbon atoms are in 2C7H5N3O6

Answers

Answer:

14

Explanation:

Using the information make a graph.

Answers

boosting this for more can see

The contents of a bucket filled from a well were in a ____ stat. If the contents were heated up enough, they would change to a ____ state.

Answers

Answer: liquid state

A gas state

Explanation:

All of the following rivers are labeled on the map above except the __________ River.
A. Danube
B. Volga
C. Lena
D. Ob

Answers

The answer for this problem would be c
The answer would be C

Give answer fast (C)
☹️☹️☹️☹️☹️☹️​

Answers

Plug in the numbers
(-3)^3 + (-3)^2 + -3 + 5
-27 + 9 - 3 + 5
-18 - 3 + 5
= -16
The answer is -16 for C

Which of these substances has a definite volume but not a definite
shape?
A. paper
B. grass
C. juice
D. water vapor

Answers

I think answer should be b. Please give me brainlest I hope this helps let me know if it’s correct or not okay thanks

What is one abiotic factor that all biotic factors need to survive??

Answers

Answer:

there r mainly three abiotic factors where all biotic factors need to thrust and survive,

They're i) Air

            ii) Water

           iii) Land

Answer:Water

Explanation:

Metals tend to — electrons and nonmetals tend to —
Electrons

Answers

Answer:

Non-metals tend to gain electrons to attain Noble Gas configurations. The have relatively high Electron affinities and high Ionization energies. Metals tend to lose electrons and non-metals tend to gain electrons, so in reactions involving these two groups, there is electron transfer from the metal to the non-metal.

If something is up higher it will have ________________ potential energy.


the same


more


less

Answers

Answer:

More

Explanation:

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