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2 years ago

Which statements best describe half-lives of radioactive isotopes? Check all that apply.

2 answers:

5 0

Answer: The half-life varies depending on the isotope. Half-lives range from fractions of a second to billions of years. The half-life of a particular isotope is constant.

Explanation: On Edgenuity!!!!

Igoryamba2 years ago

3 0

Answer:

The half-life varies depending on the isotope.

Half-lives range from fractions of a second to billions of years.

The half-life of a particular isotope is constant.

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Consider this equilibrium reaction between carbon monoxide and hydrogen gas, occurring in a sealed flexible container. CO(g) + 3

wariber [46]

Answer:

More H2(g) is added to the container : Towards products.

CO is removed from the container : Towards reactants.

More CH4(g) is added to the container : Towards reactants

H2O(g) is removed from the container : Towards products.

The contents of the container are heated up. : Towards the reactants.

The contents of the container are cooled down : Towards the products.

The pressure inside the container is increased. :Towards the products

The container is stretched to increase the volume: Towards the reactants.

Explanation: :

CO(g) + 3 H2g) → CH4(g) + H2O(g)+ heat

There is released heat, so this reaction is exothermic

If the H2 concentration is increased, the system will try to change the concentration change by shifting the balance to the right, and thus the concentration of products will increase. Towards products.

If the CO is removed, the system will try to change this situation by shifting the balance to the left, and thus the concentration of reactants will increase, the concentration of products will decrease. Towards reactants.

If the CH4 concentration is increased, the system will try to change the concentration change by shifting the balance to the left, and thus the concentration of reactants will increase. Towards reactants

If the H2O is removed, the system will try to change this situation by shifting the balance to the right, and thus the concentration of products will increase, the concentration of products will decrease. Towards products.

If the temperature is increased, the system will reduce the amount of heat released. So the balance will shift to the left. Towards the reactants.

This because the extra heat / energy must be used.

If the temperature is decreased, the system will produce more heat So the balance will shift to the right. Towards the products.

This because more heat /energy needs to be produced to make up for the loss of heat (energy).

If the pressure is increased, the system will shift to the side with fewer moles of gas. In this case, there are 4 moles on the left and 2 moles on the right. So the balance will shift to the right. Towards the products. An increase of pressure has the same effect on the equilibrium as a decrease of the volume.

If the volume is increased, this means the pressure is decreased, the system will shift to the side with most moles of gas. In this case, there are 4 moles on the left and 2 moles on the right. So the balance will shift to the left. Towards the reactants. An increase of volume has the same effect on the equilibrium as a decrease of the pressure.

6 0

2 years ago

Which lists the elements in order from least conductive to most conductive?

Savatey [412]

Answer: Option (A) is the correct answer.

Explanation:

Nitrogen is a non-metal and it is known that non-metals do not conduct electricity. Thus, it will be least conductive out of the given options.

Whereas antimony (Sb) is a metalloid. Metalloid are the substance that show properties of both metals and non-metals. Thus, antimony will conduct electricity.

On the other hand, bismuth (Bi) is a metal hence, it will conduct electricity.

Thus, we can conclude that the order from least conductive to most conductive will be nitrogen (N), antimony (Sb), bismuth (Bi).

7 0

2 years ago

Read 2 more answers

Which of the following particle diagrams represents a mixture?

QveST [7]

Answer:

???

Explanation:

i would help answer but your post has no diagrams or at least there not showing up

3 0

2 years ago

Define alkanes and give examples

LenKa [72]

the simplest organic molecules, consisting of only carbon and hydrogen and with only single bonds between carbon atoms.
Ex. Methane, Ethan, Propane, Butane

3 0

2 years ago

Consider the nuclear equation below. Superscript 235 subscript 92 upper U right arrow superscript 4 subscript 2 upper H e. What

coldgirl [10]

Answer:

$\rm_{90}^{231}\text{Th}$

Explanation:

The unbalanced nuclear equation is

$\rm _{92}^{235}\text{U} \longrightarrow \, _{2}^{4}\text{He} + X$

Let's write X as a nuclear symbol.

$\rm _{92}^{235}\text{U} \longrightarrow \, _{2}^{4}\text{He} + _{Z}^{A}\text{X}$

The main point to remember in balancing nuclear equations is that the sums of the superscripts and of the subscripts must be the same on each side of the reaction arrow.

Then

235 = 4 + A , so A = 235 - 4 = 231, and

92 = 2 + Z , so Z = 92 - 2 = 90

And your nuclear equation becomes

$\rm _{92}^{235}\text{U} \longrightarrow \, _{2}^{4}\text{He} +\, _{90}^{231}\text{X}$

Element 90 is thorium, so

$\rm X = _{90}^{231}\text{Th}$

7 0

2 years ago