4. The half-life for a 100-gram sample of radioactive element X is 5 days. How much of element X remains after 10 days have passed?
A. 25 g
B. 50 g
C. 75 g
D. 100 g

Answers

Answer 1
imma go with b : the evidence is in the text

Related Questions

The amount of matter in an object is its ____
weight
mass
volume
density

Answers

The amount of mater in a object is called matter

State the Periodic Law. Why is it so important in the study of chemistry?

Answers

Answer:

Summary. To summarize, the periodic table is important because it is organized to provide a great deal of information about elements and how they relate to one another in one easy-to-use reference. The table can be used to predict the properties of elements, even those that have not yet been discovered.

Water and chemical elements move through cycles called biogeochemical cycles. Select the best way to explain biogeochemical cycles. a. When chemicals move from the atmosphere to a living organism. b. When a chemical moves from an organism to the atmosphere then back to an organism. c. When organisms move from an organism to the atmosphere then back to an organism.

Answers

Answer:

When a chemical moves from an organism to the atmosphere then back to an organism.

Explanation:

If we look at it closely, geology and chemistry play major roles in the process of movement and recycling of inorganic matter between living organisms and their environment. This has been called the biogeochemical cycle.

Biogeochemical cycles involve movement of chemical elements among the biotic and abiotic components of the environment; from atmosphere to land to sea, and from soils to plants.

How many molecules are in 2,10 mol CO2?

0 3.79 X 1024 molecules
O 2.53 x 1024 molecules
O 1.26 X 1024 molecules
O 3.49 * 10-24 molecules

Answers

Answer:

the answer is the 3rd option

Explanation:

which is 1.26 x 1024 calculating with avogardos law

Answer:

1.26 X 1024 molecules

Explanation:

What amount of heat is required to raise the temperature of 250 grams of water by 20°C? The specific heat of water is 4180 J/Kg

Answers

Answer:

The statement means that in every interaction, there is a pair of forces acting on the two interacting objects. The size of the forces on the first object equals the size of the force on the second object. The direction of the force on the first object is opposite to the direction of the force on the second object. Forces always come in pairs - equal and opposite action-reaction force pairs. 

Explanation:

The statement means that in every interaction, there is a pair of forces acting on the two interacting objects. The size of the forces on the first object equals the size of the force on the second object. The direction of the force on the first object is opposite to the direction of the force on the second object. Forces always come in pairs - equal and opposite action-reaction force pairs. 

What element has the noble gas configuration [Ar]4s23d8

Answers

Answer:

argon

Explanation:

Answer:

Argon

Explanation:

What is a "control" in an experiment? *

Answers

Answer:

The factor that the person experimenting has control over

Explanation:

A scientific control is an experiment or observation designed to minimize the effects of variables other than the independent variable. This increases the reliability of the results, often through a comparison between control measurements and the other measurements. Hope this helped :)

A teacher puts two tablets in a glass of water. The teacher
stirs the water with a spoon until the tablets start to bubble.
Which of the following is LESS dense than water?

Answers

This question is incomplete because the options are missing; here are the options:

Which of the following is LESS dense than water?

The spoon

The glass

The tablets

The bubbles

The correct answer to this question is The bubbles

Explanation:

In general, the density of materials and substances affects their buoyancy. This implies in water less dense materials will float and those with higher density will sink. In the situation presented, the only element that is less dense than water are bubbles; this is shown by the movement of the bubbles as these originate in the bottom of the glass of water but they rise to the surface, which shows they are less dense than water.

Answer:

the bubbles

Explanation:

PLEASE HELP ME FAST THANKYOU! :)
What is a substance said to be if it evaporates easily?


A.crystallized


B.condensing


C.changing pigmentation


D.volatile

Answers

Volatile: easily evaporated substance

PLEZ HELP ANSWER. IM STUCK!

Answers

d. 3

Explanation:

because the valence electrons on O is 3

There are 3 oxygen atoms because the subscript numbers are the numbers of atoms in a molecule and O has 3

Combustion of a hydrocarbon, X, is given by the equation: 2 X + 5 O2 (g) --> 4 CO2 (g) + 6 H2O (g) ∆H = -75.0 kJ Use this information and the standard enthalpies of formation listed in the text or elsewhere, to determine the standard enthalpy of formation of the hydrocarbon, X.

Answers

Answer:

Hof(X) = - 1474.9 KJ/mol

Explanation:

The reaction equation given to us is:

2 X + 5 O2 (g) --> 4 CO2 (g) + 6 H2O (g) ∆H = -75.0 kJ

Now, the equation for the standard enthalpy of formation of the reaction is written as follows:

ΔH = 4*Hof(CO2(g)) + 6*Hof(H2O(g)) - 2*Hof(X) - 5*Hof(O2(g))

where,

ΔH = - 75 KJ

Hof(CO2(g)) = Standard Heat of Formation of CO2(g) = -393.5 KJ/mol

Hof(H2O(g)) = Standard Heat of Formation of H2O(g) = -241.8 KJ/mol

Hof(X) = Standard Heat of Formation of X = ?

Hof(O2(g)) = Standard Heat of Formation of O2(g) = 0 KJ/mol

Therefore,

-75 KJ = (4)(-393.5 KJ/mol)+ (6)(-241.8 KJ/mol) - (2)(Hof (X)) - (5)(0 KJ/mol)

- 75 KJ + 3024.8 KJ = - (2)(Hof(X))

Hof(X) = -2949.8 KJ/2 mol

Hof(X) = - 1474.9 KJ/mol

1) Equal masses of different substances have the same volumes.​

Answers

Answer:

True

Explanation:

what determines the atomic number of the atom

Answers

Answer:

the number of protons

Explanation:

that's it

To which family on the Periodic Table does this Bohr Model belong?

Answers

Answer:

As the valance shell have 7 valance electrons .

It belongs to halogen family (group 17).

How would you calculate the gravitational potential energy of a 2 kg bottle of soda falling off of a kitchen table that is 0.76 m tall ?

Answers

Answer:

14.9 Joules .

Explanation:

P. E. = m g h

= 2 * 9.8 * 0.76

= 14.9 Joules to the nearest tenth.

Answer:

2*0.76*97

Explanation:

Viruses and bacteria

Answers

Answer:

Whats the question lolzzzz

Explanation:

PLEASE HELP ASAP!!
If an element has the atomic number of 13 and a mass number of 27, what
is that element?
-cobalt
-aluminum
-silicon

Answers

Aluminum is your answer :)

C3H8 +5O2→ 3 CO2 + 4 H2O
In the reaction above, what is the total number of moles of reactants consumed when 1.00 mole of CO2 is produced?

a
0.33 mol
b
2.00 mol
c
1.33 mol
d
1.50 mol

Answers

Answer:

1.33

Explanation:

sorry if im wrong :(

The isotope Np-238 has a half life of 2.0 days if 96 grams of it were present on Monday how much will remain six days later

Answers

Answer:

12 grams

Explanation:

For any radioactive substance

the amount of substance left after n half life  is given by = [tex]x/2^n[/tex]

where x the original amount of substance.

____________________________________________

Half life of isotope Np-238 = 2 days

total no of days = 6

no of half life =total no of days/Half life of isotope Np-238 = 6/2 = 3

thus,

for our problem n = 3

initial amount of Np-238 = 96 grams

thus,

the amount of substance left after 3 half life = 96/2^3 = 96/8 = 12 grams.

Thus, 12 grams will be left after six days.

Help me please !!!
Which of the following can be inferred from the diagram above that shows the dependence of potential Energy on the Internuclear distance between two atoms?

A)The atoms form a bond with a bond length of 25 pm
B)The atoms form a bond with a bond length of 75 pm
с)The net force between the atoms is attractive at 25 pm
D)The net force between the atoms is attractive at 75 pm

Answers

Answer:

B)The atoms form a bond with a bond length of 75 pm

In a water molecule, oxygen attracts electrons more strongly
than the hydrogens do because an oxygen atom contains
more
in its nucleus.
Enter the answer

Answers

The answer is False

what dose pH mean on the periodic table​

Answers

this is power of hydrogen

At what time of day is sunlight strongest - in the early morning (when the Sun has just risen)
or at noon (when the Sun reaches its highest point)?

Answers

Answer:

noon is the answer. Hope it helps

Answer:

Noon

Explanation:

Hope this helps <3

1 pts
Define valence electrons.
o Valence electrons are the electrons on the outermost energy level of an
atom.
o Valence electrons are the electrons on the innermost energy level of an
atom.
Valence electrons are the electrons in the middle energy level of an
atom.
Valence electrons are the electrons on the inside of the nucleus of the
atom.

Answers

Answer:

Valence electrons are the electrons on the outermost energy level of an

atom.

The correct answer will be Valence electrons are the electrons on the outermost energy level of an atom.

which of the following pairs would have
a the
larger size
K or k+ ?
Explain your
ur answer.​

Answers

Answer: Here u go!

Explanation:

In other words, "K"^(+) has bigger effective nuclear charge than "Cl"^(-), which translates to a bigger net positive charge felt by the outermost electrons. This will compress the energy levels a bit and make the ionic radius smaller for the potassium cation. Therefore, the chloride anion will have the larger atomic radius.

Hope this helps ma dude!

Which element has the most metallic characteristics?
O Selenium (Se)
Arsenic (As)
O Germanium (Ge)
O Gallium (Ga)

Answers

Answer:

(Ge)

Explanation:

I'm just taking a wild guess really!

HELP ASAP!! FILL IN THE BLANKS! will be brainliest!!!

Answers

Answer:

Don't mark me brainliest because of this but I'm pretty sure your supposed to give us the words because teachers don't give you things like that without the words you will the answer in with.

Answer:

Same as number of NUETRONS

POSITIVE charge

number of protons is the same as the atomic NUMBER

Located in the Nucleus

Larger mass than ELECTRONS

Explanation:

GOOD LUCK

How many elements are present in the compound?
Mg2As3COHNi2

Answers

Answer: 6

Explanation: none needed lol

Elements in the same _____ on the periodic table have the same number of valence electrons.

Answers

Elements in the same [column or group] on the periodic table have the same number of valence electrons.

Nitrogen (N) is element number 7 in the periodic table. It has a mass number of 14. Nitrogen
has gained 3 electrons. Nitrogen is a/an___.
a. Anion
bcation
c. Isotope
d. All of the above

Answers

The answer is ISOTOPE
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