All categories

3 years ago

True or False: The Periodic Table of Elements is in alphabetical order to make locating elements easier.

Chemistry

1 answer:

viva [34]3 years ago

3 0

Answer:

False

Explanation:

The periodic table is in order of their atomic number. If that were true, helium would not come before boron, for example.

You might be interested in

How are states of matter different at an atomic scale?

nalin [4]

Answer:

The bonds that exist between their atoms and molecules differ on an atomic scale.

Explanation:

The three basic states of matter are solid, liquid, and gas. The major difference between them is the strength of the bonds that hold their molecules together. This affects the way that the molecules interact with each other.

The intermolecular forces binding solids together are very strong. This makes solids rigid and not able to move about freely, but rather, only able to vibrate about a mean position.

The intermolecular forces binding liquid atoms together are a lot weaker than that of solids. This makes liquids able to flow.

The intermolecular forces binding gas molecules together are the weakest. As a result, the gases can move about freely and occupy no definite volume.

7 0

3 years ago

Question 9 (1 point)

pantera1 [17]

Answer:

8 moles of C

Explanation:

From the question given above, the following equation was obtained:

3A + 2B —> 6C

From the equation above,

3 moles of A reacted to produce 6 moles of C.

Thus, the number of mole of C produced by reacting 4 moles of A can be obtained as follow:

From the equation above,

3 moles of A reacted to produce 6 moles of C.

Therefore, 4 moles of C will react to produce = (4 × 6)/3 = 8 moles of C

Thus, 8 moles of C can be obtained from the reaction of 4 moles of A with excess B

6 0

3 years ago

For most solids at room temperature, the specific heat is determined by oscillations of the atom cores in the lattice (each osci

Cloud [144]

Answer:

The specific heat of copper is $C= 392 J/kg\cdot ^o K$

Explanation:

From the question we are told that

The amount of energy contributed by each oscillating lattice site is $E =3 kT$

The atomic mass of copper is $M = 63.6 g/mol$

The atomic mass of aluminum is $m_a = 27.0g/mol$

The specific heat of aluminum is $c_a = 900 J/kg-K$

The objective of this solution is to obtain the specific heat of copper

Now specific heat can be defined as the heat required to raise the temperature of 1 kg of a substance by $1 ^o K$

The general equation for specific heat is

$C = \frac{dU}{dT}$

Where $dT$ is the change in temperature

$dU$ is the change in internal energy

The internal energy is mathematically evaluated as

$U = 3nk_BT$

Where $k_B$ is the Boltzmann constant with a value of $1.38*10^{-23} kg \cdot m^2 /s^2 \cdot ^o K$

T is the room temperature

n is the number of atoms in a substance

Generally number of atoms in mass of an element can be obtained using the mathematical operation

$n = \frac{m}{M} * N_A$

Where $N_A$ is the Avogadro's number with a constant value of $6.022*10^{23} / mol$

M is the atomic mass of the element

m actual mass of the element

So the number of atoms in 1 kg of copper is evaluated as

$m = 1 kg = 1 kg * \frac{10000 g}{1kg } = 1000g$

The number of atom is

$n = \frac{1000}{63.6} * (6.0*0^{23})$

$= 9.46*10^{24} \ atoms$

Now substituting the equation for internal energy into the equation for specific heat

$C = \frac{d}{dT} (3 n k_B T)$

$=3nk_B$

Substituting values

$C = 3 (9.46*10^{24} )(1.38 *10^{-23})$

$C= 392 J/kg\cdot ^o K$

5 0

3 years ago

The number of protons in an atom is known as its .......... ...........?

Tanzania [10]

Answer:

Atomic number

Explanation:

Atomic number is the number of protons, and therefore also the total positive charge, in the atomic nucleus. The Rutherford–Bohr model of the hydrogen atom (Z = 1) or a hydrogen-like ion (Z > 1).

7 0

3 years ago

Kylie has two glasses with equal volumes of pure water. She adds 40 g of sugar to one of the glasses of water and 40 g of salt t

Ksenya-84 [330]

Sugar is an organic compound and does not form ions in solution. Salt is mostly sodium chloride and forms negative Cl ions in solution and positive Na ions. These ions affect electrical conductivity making salt solution a good conductor of electricity. Pure water is not a good conductor of electricity, but an impurity such as salt increases its conductivity. Sugar solution does not enhance water’s electrical conductivity.

3 0

4 years ago

Read 2 more answers