1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
mr_godi [17]
3 years ago
15

What are the elements in the first period

Chemistry
2 answers:
aliina [53]3 years ago
6 0

Answer:

Explanation:

There are only two elements in the first period: hydrogen and helium. We can explain why there is less elements in the first row in modern theories of atomic structure.

Bond [772]3 years ago
6 0

Answer:

"Hydrogen and Helium". Hydrogen and Helium are the elements of the first period in the modern periodic table.

Explanation:

You might be interested in
Calculate the amount of heat needed to melt 99.9 g of solid acetic acid (HCH,CO2) and bring it to a temperature of 85.1 °C. Roun
Nadusha1986 [10]

Q = 1.161 J/kg of heat is required to melt 99.9 g of solid acetic acid (HCH,CO2). Q = mL(Latent heat is the energy emitted or absorbed by a body while changing it state ). (Latent heat is the energy released or absorbed by a body while changing it state ).

<h3>How to fix?</h3>

Apply the equation Q = mL where:

Energy is Q. (J)

m = Mass (g)

L = Acetic acid's latent heat of fusion 192(J/g) = J/g

Q is equal to 0.099 kg times 11.73 kj/mol.

Q = 1.161J/kg.

<h3>What is latent heat, and what varieties are there?</h3>

Latent heat is the amount of energy that a substance experiencing a change in state, such as ice turning into water or water turning into steam, can absorb or release while maintaining a constant temperature and pressure. Types: The material exists in three states: solid, liquid, and gaseous.

<h3>What does "sensible heat" mean?</h3>

Heat that can actually be felt is considered to be sensible heat. Instead of the phase shifting, energy is what causes the temperature to vary as it moves from one system to another. For instance, it warms the water instead of melting the ice.

Learn more about specific heat on:

brainly.com/question/11297584

#SPJ4

3 0
1 year ago
Calculate the mass of Na2O that can be produced by the chemical reaction of 4.0 grams of sodium with excess oxygen in the reacti
e-lub [12.9K]

Answer:

The mass of Na₂O that can be produced by the chemical reaction of 4.0 grams of sodium with excess oxygen in the reaction is 5.39 grams.

Explanation:

You know  the balanced reaction:

4 NA + O₂ ⟶ 2 Na₂O

By stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction) react and are produced:

  • Na: 4 moles
  • O₂: 1 mole
  • Na₂O: 2 moles

Being:

  • Na: 23 g/ole
  • O: 16 g/mole

the molar mass of the compounds participating in the reaction is:

  • Na: 23 g/mole
  • O₂: 2*16 g/mole= 32 g/mole
  • Na₂O: 2*23 g/mole +16 g/mole=  62 g/mole

Then by stoichiometry of the reaction they react and are produced:

  • Na: 4 moles* 23 g/mole= 92 g
  • O₂: 1 mole*32  g/mole= 32 g
  • Na₂O: 2 moles* 62 g/mole= 124 g

Then you can apply the following rule of three: if 92 grams of Na produce 124 grams of Na₂O, 4 grams of Na, how much mass of Na₂O does it produce?

massofNa_{2}O =\frac{4 grams of Na*124 gramsofNa_{2}O }{92 grams of Na}

mass of Na₂O=5.39 g

<em><u>The mass of Na₂O that can be produced by the chemical reaction of 4.0 grams of sodium with excess oxygen in the reaction is 5.39 grams.</u></em>

8 0
2 years ago
Which solution has a molality of 0.25m nacl?
Solnce55 [7]

Molality can be expressed by moles of solute over kilograms of solvent. The question asks the molality of 0.25m NaCl. 0.25m NaCl is equal to 0.25 moles of NaCl over 1 kg of water.

5 0
3 years ago
Read 2 more answers
11,12,13,14 please...
jekas [21]
11. D
12.C
13. For 13 i would say B but not so sure
14. A
5 0
2 years ago
What types of predictions can be made using the Periodic Table?
Andrej [43]
Periodic trends are specific patterns that are present in the periodic table that illustrate different aspects of a certain element, including its size and its electronic properties. Major periodic trends include: electronegativity, ionization energy, electron affinity, atomic radius, melting point, and metallic character. Periodic trends, arising from the arrangement of the periodic table, provide chemists with an invaluable tool to quickly predict an element's properties. These trends exist because of the similar atomic structure of the elements within their respective group families or periods, and because of the periodic nature of the elements.
8 0
3 years ago
Other questions:
  • The half-life of tritium (H-3) is 12.3 years. If 48.0mg of tritium is released from a nuclear power plant during the course of a
    15·1 answer
  • What happens if a species is unable to adapt to a changing environment.
    11·1 answer
  • What are the advantages of using a computer over a graphing calculator
    15·1 answer
  • Lines on a map joining places that have the same temperature?
    7·2 answers
  • Answering just one is fine. Please help. It's due in less than an hour
    6·2 answers
  • Why do scientists often use bacteria to produce medicines?​
    12·2 answers
  • Help me pleaseeeeee​
    15·1 answer
  • 2) A common "rule of thumb" -- for many reactions around room temperature is that the
    8·1 answer
  • Why do we feel cold when we touch the iron?
    10·1 answer
  • Which of the following is an oxidation? Select all that apply
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!