Answer:
D. He showed that most of an atom's mass was located in the atom's
nucleus.
Explanation:
Ernest Rutherford changed the atomic model because of his experiment which was the gold foil experiment. A beam of alpha particles was aimed at a piece of gold foil, most particles passed through but some were scattered backward which showed that the middle of an atom (nucleus) is the where most of the mass is located.
The given mass of cobalt chloride hydrate = 2.055 g
A sample of cobalt chloride hydrate was heated to drive off waters of hydration and the anhydrate was weighed.
The mass of anhydrous cobalt chloride = 1.121 g anhydrate.
The mass of water lost during heating = 2.055 g - 1.121 g = 0.934 g
Converting mass of water of hydration present in the hydrate to moles using molar mass:
Mass of water = 0.934 g
Molar mass of water = 18.0 g/mol
Moles of water = 
Answer:
The Earth is shaped by many geological processes. ... Processes caused by forces from within the Earth are endogenous processes. Exo is a prefix meaning "out", and endo is a prefix meaning "in". Many exogenous (extraterrestrial) forces are caused by other bodies in the Solar System.
Answer:
The number of copper atoms 12.405 ×10²³ atoms.
The number of silver atoms 13.13 ×10²³ atoms.
Beaker B have large number of atoms.
Explanation:
Given data:
In beaker A
Number of moles of copper = 2.06 mol
Number of atoms of copper = ?
In beaker B
Mass of silver = 222 g
Number of atoms of silver = ?
Solution:
For beaker A.
we will solve this problem by using Avogadro number.
The number 6.022×10²³ is called Avogadro number and it is the number of atoms in one mole of substance.
While we have to find the copper atoms in 2.06 moles.
So,
63.546 g = 1 mole = 6.022×10²³ atoms
For 2.06 moles.
2.06 × 6.022×10²³ atoms
The number of copper atoms 12.405 ×10²³ atoms.
For beaker B:
107.87 g = 1 mole = 6.022×10²³ atoms
For 222 g
222 g / 101.87 g/mol = 2.18 moles
2.18 mol × 6.022×10²³ atoms = 13.13 ×10²³ atoms
Answer:
D. Hydrogen bonds between complementary base pairs89
Explanation:
A DNA molecule is composed of two long polynucleotide chains made of four types of nucleotide subunits, two purines (adenine and guanine) and two pyrimidines (cytosine and thymine). These nucleotides are joined by covalent bonds forming a phosphate-sugar backbone. <em>These strands are held to one another with hydrogen bonds between the base portions of complementary nucleotides.</em>
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