1. Radioactive decay of 40K atoms in an igneous rock has resulted in a ratio of 25 percent 40K atoms to 75 percent 40Ar and 40Ca atoms. How many years old is this rock?

Answers

Answer 1

Answer: 1/2 of the original parent has decayed, thus one half- life has passed, and the rock is 1.3 billion = 1300 million years old

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Another name for the activated complex is _____.a. energy barrierb. transition statec. rate limiterd. collision group
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Who described atoms as small spheres that could not be divided into anything smaller?

Answers

Chemist John Dalton described atoms as small spheres that could not be divided into anything smaller.

Answer:

Chemist John Dalton

Solid samples of the element phosphorus can be white, black, or red in color. The variations in color are due to different(1) atomic masses
(2) molecular structures
(3) ionization energies
(4) nuclear charges

Answers

Answer:

Due to molecular structures.

Explanation:

The different forms of phosphorus (white, black or red) are allotropes of phosphorus.

They differ in molecular structures.

White phosphorus: It has four phosphorus which form a tetrahedral shape.

Black phosphorus : It has orthorhombic structure and due to interlinked six membered rings, it is least reactive.

Red phosphorus: It is formed on heating white phosphorus. It is initially amorphus and turns crystalline on further heating.

Solid samples of the element phosphorus can be white, black, or red in color. The variations in color are due to different Molecular structures.

If 3.00 g of limestone reacted, what mass of calcium chloride would be produced?A) Calcium chloride
B) Carbon dioxide
C) water

Answers

a) CaCO₃ + 2 HCl = CaCl₂ + H₂O + CO₂
↓ ↓
1 mole 1 mole

molar mass :

CaCO₃ = 100.0 g/mol CaCl₂ = 111 g/mol

100 g CaCO₃ ------------- 111 g caCl₂
3.00 g CaCO₃ --------------- ?

3.00 * 111 / 100 =

333 / 100 = 3.33 g of CaCl₂
________________________________________

b) molar mass CO₂ = 44.0 g/mol

100 g CaCO₃ ---------- 44.0 g CO₂
3.00 g CaCO3 ------------- ?

3.00 * 44 / 100 =

132 / 100 = 1.32 g of CO2
____________________________________

c) molar mass H₂O = 18.0 /mol

100 g CaCO3 ------- 18.0 g
3.00 g CaCO3 ------- ?

3.00 * 18.0 / 100 =

54 / 100 = 0.54 g of H₂O
___________________________________

hope this helps!

What is the word equation for molecules of magnesium reacting with molecules of oxygen to produce molecules of magnesium oxide?magnesium + magnesium oxide = oxygen
magnesium + oxygen =magnesium oxide
magnesium oxide = magnesium
magnesium + oxygen magnesium + oxygen

Answers

Answer: magnesium + oxygen =magnesium oxide

Explanation: When Magnesium reacts with the molecules of oxygen , Magnesium oxide is produced.

Mg (s) + O (g) → MgO (s)

In this equation, both magnesium and oxygen are present in its elemental state.

Magnesium is present in solid form and oxygen is present in gaseous form.

The Bonding between the Magnesium and the oxygen is purely IONIC bonding as Magnesium loses its 2 valence electrons to complete its octet and oxygen gains its electrons to make its electron count 8 in the valence shell.

Answer: (B) Magnesium + oxygen =magnesium oxide

Explanation:

What has the strongest intermolecular forces of attraction?

Answers

The strength of intermolecular forces of attraction varies depending on the type of molecules involved. In general, the order of increasing strength of intermolecular forces is as follows:

1. **London Dispersion Forces (Van der Waals Forces):** These are the weakest intermolecular forces and occur in all molecules. They are caused by temporary fluctuations in electron distribution, leading to temporary partial charges. London dispersion forces are stronger in larger and more polarizable molecules.

2. **Dipole-Dipole Forces:** These forces occur between polar molecules with permanent dipoles. They are stronger than London dispersion forces and result from the attraction between the positive end of one molecule and the negative end of another.

3. **Hydrogen Bonding:** This is the strongest type of intermolecular force. It occurs when hydrogen is bonded to a highly electronegative atom (such as nitrogen, oxygen, or fluorine) and is attracted to another electronegative atom in a different molecule. Hydrogen bonds are responsible for the unique properties of substances like water and ammonia.

So, hydrogen bonding generally represents the strongest intermolecular force of attraction among these three types. However, it's important to note that the actual strength of these forces can also depend on factors such as molecular size, shape, and temperature.

Hope you understand

At standard pressure, CH4 boils at 112 K and H2O boils at 373 K. What accounts for the higher boiling point of H2O at standard pressure?(1) covalent bonding (3) hydrogen bonding(2) ionic bonding (4) metallic bonding

Answers

The answer is (3) hydrogen bonding. This is a question of intermolecular forces. H2O is highly polar (the O—H bond is particularly polar since O is so electronegative), and CH4 is about as nonpolar as it gets. So, while H2O molecules are held together by relatively strong hydrogen bonds (which, keep in mind, are not actually bonds), CH4 molecules are held together by much weaker London dispersion/Van der Waals forces. Thus, it takes more thermal energy to separate H2O molecules, and H2O therefore has a higher boiling point.

Answer:

Hydrogen bonding

Explanation:

Castle learning

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What are the three elements found in a molecule of calcium carbonate? Give their atomic numbers and chemical symbols. How many atoms of each are found in one molecule of calcium carbonate?