All categories

3 years ago

PERIODIC TABLE TEST WILL GIVE BRAINLIEST!

Chemistry

2 answers:

klio [65]3 years ago

7 0

Answer:

1. True

2. True

3. True

4. Vertical

5. periods

6. All the given options

7. Atomic

8. False

9. False

10. 116

Thank you again :-D

Neko [114]3 years ago

6 0

Answer:

1. True

2. True

3. True

4. B. vertical

5. B. periods

6. A, B, C, D

7. C. Atomic

8. B. false

9. A. True

10. A. 112

Explanation:

1. Helium is a natural gas found in the atmosphere and below ground.

2. Neon is also natural gas found in Earth's atmosphere and can be seen on the periodic table.

3. An element is considered a pure substance because it is made up of only one type of atom and cannot be broken down into a simpler form.

4. Families/groups go up and down (vertical), while periods go across (horizontal)

5. As I just mentioned, periods run horizontally on the Periodic table.

6. Matter is everything that takes up space and has mass. Therefore, all of the given answers consist of matter. Why else would they matter? :)

7. The title of the "Most Accurate Clock In The World" goes to the British atomic clock at UK's National Physical Laboratory (NPL).

8. Almost 99% of the mass of the human body is made up of six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Only about 0.85% is composed of another five elements: potassium, sulfur, sodium, chlorine, and magnesium. Therefore, we consist of more that 99%.

9. A grain of sand is relatively small; about the size of one atom.

10. The periodic table has 112 elements because there were 112 elements before IUPAC reviewed elements 113, 115, 117 and 118, and decided to give them official names and symbols. This was relatively recent. The total number of elements is 118 though.

I would like to apologize in advance if any of these were incorrect.

You might be interested in

Carbon, hydrogen and ethane each burn exothermically in an excess of air. AHⓇ =-393.7 kJ mol. C(s) + O2(g) → CO2(g) H2(g) + % O2

Salsk061 [2.6K]

Answer: The $\Delta H^o_{rxn}$ for the reaction is 51.8 kJ.

Explanation:

Hess’s law of constant heat summation states that the amount of heat absorbed or evolved in a given chemical equation remains the same whether the process occurs in one step or several steps.

According to this law, the chemical equation is treated as ordinary algebraic expressions and can be added or subtracted to yield the required equation. This means that the enthalpy change of the overall reaction is equal to the sum of the enthalpy changes of the intermediate reactions.

The chemical equation for the reaction of carbon and water follows:

$2C(s)+2H_2(g)\rightarrow C_2H_4(g)$ $\Delta H^o_{rxn}=?$

The intermediate balanced chemical reaction are:

(1) $C(s)+O_2(g)\rightarrow CO_2(g)$ $\Delta H_1=-393.7kJ$ ( × 2)

(2) $H_2+\frac{1}{2}O_2(g)\rightarrow H_2O(l)$ $\Delta H_2=-285.9kJ$ ( × 2)

(3) $2C_2H_4(s)+2O_2(g)\rightarrow 2CO_2(g)+2H_2O(l)$ $\Delta H_3=-1411kJ$

The expression for enthalpy of the reaction follows:

$\Delta H^o_{rxn}=[2\times \Delta H_1]+[2\times \Delta H_2]+[1\times (-\Delta H_3)]$

Putting values in above equation, we get:

$\Delta H^o_{rxn}=[(2\times (-393.7))+(2\times (-285.9))+(1\times -(-1411))]=51.8kJ$

Hence, the $\Delta H^o_{rxn}$ for the reaction is 51.8 kJ.

6 0

3 years ago

The compound 3-methylpentane is an example of

Cerrena [4.2K]

Answer:

A) An Alkaline

Explanation:

An alkane that is pentane which is substituted by a methyl group at position 3. It is used as a solvent in organic synthesis, as a lubricant and as a raw material for producing carbon black.

3 0

3 years ago

142 amu of chlorine would contain

zhuklara [117]

Answer: There are four atoms

Explanation: mass of Cl atom is 35.45 amu

Amount of atoms n = m/M = 142 / 35.45 = 4

5 0

3 years ago

ICMP scanning involves in checking for the live systems, which can be done by sending the following ping scan request to a host.

abruzzese [7]

Answer:

ICMP Echo Request

Explanation:

ICMP Echo Request is a form of probe or message sent by a user to a destination system.

5 0

3 years ago

A plot of binding energy per nucleon (Eb/ A) versus the mass number (A) shows that nuclei with a small mass number have a small

juin [17]

Answer:

a) 1.12 MeV / nucleon

b) 5.62 MeV / nucleon

c) 8.80 MeV / nucleon

d) 8.56 MeV / nucleon

we can conclude that the binding energy has a maximum value for nuclei with a mass around 60

Explanation:

Binding energy = ( Δm * 931.5 ) MeV

Binding energy per nucleon = Binding energy in / Number of nucleon

a) ²H = 1 neutron , 1 proton = 2 nucleons

Given that the theoretical mass = 2.0141 u

Actual mass = 1.0078 u + 1.0087 u = 2.0165 u

Δm = 2.0165 u - 2.0141 u = 2.4 * 10^-3 u

∴ Binding energy per nucleon = ( 2.4 * 10^-3 * 931.5 ) MeV / 2 nucleons

= 1.12 MeV / nucleon

b) ⁷Li = 3 protons , 4 neutrons = 7 nucleons

theoretical mass = 7.0160 u

Actual mass = ( 3 * 1.0078 ) + ( 4 * 1.0087 ) = 7.0582 u

Δm = ( 7.0582 u - 7.0160 u ) = 0.0422 u

∴ Binding energy per nucleon = ( 0.0422 * 931.5 ) / 7

= 5.62 MeV / nucleon

C) ⁶²Ni = 28 protons , 34 neutrons = 62 nucleons

Theoretical mass = 61.9283 u

Actual mass = ( 28 * 1.0078 ) u + ( 34 * 1.0087 ) u

= 62.5142 u

Δm = 0.5859 u

∴ Binding energy per nucleon = ( 0.5859 * 931.5 ) / 62

= 8.80 MeV / nucleon

D) ¹¹⁰Cd = 48 protons , 62 neutrons = 110 nucleons

Theoretical mass = 109.9030 u

Actual mass = ( 48 * 1.0078 ) + ( 62 * 1.0087 )

= 110.9138 u

Δm = ( 110.9138 - 109.9030 ) = 1.0108 u

∴ Binding energy per nucleon = ( 1.0108 * 931.5 ) / 110

= 8.56 MeV / nucleon

hence we can conclude that the binding energy has a maximum value for nuclei with a mass around 60

3 0

3 years ago