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3 years ago

Explain why the following statements are true:

1 answer:

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1.Atoms combine to form molecules which in turn are what makes up matter.

2.Electrons carry negative charges and protons carry positive charges. While protons have far more mass the number of protons and electrons in a stable atom is the same. These charges cancel each other out. If there is an imbalanced then the atom is radioactive and decays until it reaches stability.

3.According to the kinetic theory of matter, "All matter is made up of atoms and molecules that are constantly moving. When heat is added to a substance, the molecules and atoms vibrate faster. As atoms vibrate faster, the space between atoms increases."

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Which statement correctly compares barium nitrate (Ba(NO3)2) and scandium nitrate (Sc(NO3)3)?

3241004551 [841]

<h2>D. They contain the same number of elements.</h2>

Explanation:

The formula (Ba(NO3)2) contains 9 atoms.

1 Barium atom (Ba)

Contains 2 NO3 groups -

2 Nitrogen atoms (N) x 2

6 Oxygen atoms (O3) x 2

3 Elements in total

The formula (Sc(NO3)3) contains 13 atoms.

1 Scandium atom (Sc)

Contains 3 NO3 groups -

3 Nitrogen atoms (N) x 3

9 Oxygen atoms (O3) x 3

3 Elements in total

They do not have the same number of atoms.

They do not have the same number of oxygen atoms.

They do not contain the same number of NO3 groups.

They do have the same number of elements.

8 0

4 years ago

For the following pair, indicate which element has the lower first ionization energy: Match the words in the left column to the

emmainna [20.7K]

Answer:

For 1: The correct answer is Ge.

For 2: The correct answer is Te.

For 3: The correct answer is Ba.

For 4: The correct answer is Ag.

Explanation:

Ionization energy is defined as the energy required to remove an electron from the outermost shell of an isolated gaseous atom. It is represented as $E_i$

$X(g)\rightarrow X^+(g)+1e^-;E_i$

Ionization energy increases as we move from left to right in a period. This happens because the atomic radius of an element decreases moving across a period, which increases the effective attraction between the negatively charged electrons and positively-charged nucleus. Hence, the removal of electron from the outermost shell becomes difficult and requires more energy.

Ionization energy decreases on moving from top to bottom in a group. This happens because the number of shells increases as we move down the group. The electrons get added in the new shell. So, the shielding of outermost electrons from the inner ones is more which decreases the attraction between the electrons and the nucleus. Hence, the removal of electron from the outermost shell becomes easy and requires less energy.

For the given options:

Option 1:

Chlorine is the 17th element of the periodic table belonging to Period 3 and Group 17.

Germanium is the 32nd element of the periodic table belonging to Period 4 and Group 14.

Hence, germanium will have smaller first ionization energy.

Option 2:

Tellurium is the 52nd element of the periodic table belonging to Period 5 and Group 16.

Selenium is the 34th element of the periodic table belonging to Period 4 and Group 16.

Hence, tellurium will have smaller first ionization energy.

Option 3:

Barium is the 56th element of the periodic table belonging to Period 6 and Group 2.

Titanium is the 22nd element of the periodic table belonging to Period 4 and Group 4.

Hence, barium will have smaller first ionization energy.

Option 4:

Copper is the 29th element of the periodic table belonging to Period 4 and Group 11.

Silver is the 47th element of the periodic table belonging to Period 5 and Group 11.

Hence, silver will have smaller first ionization energy.

5 0

3 years ago

23 How many moles are in 500g of Calcium Nitrate? 10 M

Harman [31]

500 grams Calcium Nitrate to mol= 3.04715

6 0

4 years ago

How much heat, in calories, is given off when 1.25 grams of silver is cooled from 100.0°C to 80.0°C? (The specific heat of silve

White raven [17]

1.43cal is the answer

4 0

4 years ago

Read 2 more answers

What is the mass of solute dissolved in 50,0 g of 12.5% saline solution? A) 7.148 B) 6.258 C) 43.88 D) 4.00 g

Marizza181 [45]

Answer:

6.25 grams is the mass of solute dissolved.

Explanation:

w/w % : The percentage mass or fraction of mass of the of solute present in total mass of the solution.

$w/w\%=\frac{\text{Mass of solute}}{\text{Mass of solution}}\times 100$

Mass of the solution = 50.0 g

Mass of the solvent = x

w/w % = 12.5%

$12.5\%=\frac{x}{50.0 g}\times 100$

x = 6.25 g

6.25 grams is the mass of solute dissolved.

6 0

3 years ago