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-BARSIC- [3]
3 years ago
8

A sample of polonium-210 has an initial mass of 390 milligrams (mg). If the half-life of polonium-210 is 36 days, how many mg of

the sample remains after 72 days?
A.
392 mg

B.
195 mg

C.
97.5 mg

D.
48.75 mg
Chemistry
1 answer:
Over [174]3 years ago
3 0

Answer:

C

Explanation:

I got this question right on my test.

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What is the total number of protons, neutrons, and electrons in a cadmium, Cd, atom that has a mass number of 112?
Triss [41]

Answer:

Number of Protons 48

Number of Neutrons 64

Number of Electrons 48

Explanation:

The mass number of an atom is the sum of the number of protons and neutrons in the nucleus of that atom

6 0
3 years ago
I need help with this packet
Anna11 [10]
Q1. An inorganic compound is a compound where the main constituent or substance is not that of Carbon but predominantly other elements, such as I, N etc. An organic compound is one where the main substituent or main element, the element found in much greater amounts would be Carbon.

Q2. Water is considered a very good solvent, because of its ability to dissolve well with mostly all other polar compounds, and produce ions from those ionic compounds.

A. Hydrogen atoms
B. Oxygen atom.
5 0
3 years ago
Near Cozumel, Mexico, a scuba diver goes down 60 ft to look at the sea creatures. As she descends, the air pressure increases. W
Rudik [331]

Answer: Boyle's Law

Explanation:

Boyle's Law which is also called Mariotte's law was formulated by physicist Robert Boyle in 1662.

It posits that the pressure (p) of a given quantity of gas varies inversely with its volume (v) at constant temperature.

As the Scuba Diver went deeper, the volume of air dropped so the pressure increased.

Please do react or comment to the answer if you have any issues or if you feel like this helped you so we can help others as well. Thank you.

5 0
3 years ago
Determine total H for bonds broken and formed, the overall change in H, and the final answer with units. Is it ENDOthermic or EX
Mrac [35]
  • E(Bonds broken) = 1371 kJ/mol reaction
  • E(Bonds formed) = 1852 kJ/mol reaction
  • ΔH = -481 kJ/mol.
  • The reaction is exothermic.
<h3>Explanation</h3>

2 H-H + O=O → 2 H-O-H

There are two moles of H-H bonds and one mole of O=O bonds in one mole of reactants. All of them will break in the reaction. That will absorb

  • E(Bonds broken) = 2 × 436 + 499 = 1371 kJ/mol reaction.
  • ΔH(Breaking bonds) = +1371 kJ/mol

Each mole of the reaction will form two moles of water molecules. Each mole of H₂O molecules have two moles O-H bonds. Two moles of the molecule will have four moles of O-H bonds. Forming all those bond will release

  • E(Bonds formed) = 2 × 2 × 463 = 1852 kJ/mol reaction.
  • ΔH(Forming bonds) = - 1852 kJ/mol

Heat of the reaction:

  • \Delta H_{\text{rxn}} = \Delta H(\text{Breaking bonds}) + \Delta H(\text{Forming bonds})\\\phantom{ \Delta H_{\text{rxn}}} = +1371 + (-1852) \\\phantom{ \Delta H_{\text{rxn}}} = -481 \; \text{kJ} / \text{mol}

\Delta H_{\text{rxn}} is negative. As a result, the reaction is exothermic.

3 0
3 years ago
Astronomers studying the planet of Rhombus have detected sedimentary rock on its surface. One astronomer wonders if material in
Fed [463]

Answer:

igneous rock CAN become sedimentary rock through a process called ROCK CYCLE.

Explanation:

Rocks can be defined as solid structures of minerals that are formed naturally over a period of time. They are grouped into three main types which includes the following:

- igneous rock

- sedimentary rocks and

- metamorphic rocks.

Rocks are capable of transforming from one type to another through a process known as rock cycle. There are two forces that brings about this process which includes:

- The internal force : this is the Earth’s internal heat engine, which moves material around in the core and the mantle and leads to slow but significant changes within the crust.

- The external force: this is the the hydrological cycle, which is the movement of water, ice, and air at the surface, and is powered by the sun.

Molten magma cools to form either extrusive igneous rock or intrusive igneous rock. With time they undergo weathering, eroded, transported, and then deposited as sediments which are being compressed and cemented into SEDIMENTARY ROCKS. Again through the above mentioned forces, different kinds of rocks are either uplifted, to be re-eroded, or buried deeper within the crust where they are heated up, squeezed, and changed into METAMORPHIC ROCK.

Therefore the material in this sedimentary rock found in Rhombus planet used to be in igneous rock deep in Rhombus's interior due to continuous rock cycling on the planet. I hope this helps, thanks.

5 0
3 years ago
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