What were the first 5 planets that were observed? Why were those the only ones? Help pls!

Color, hardness, solubility, mass, density, volume, and melting point are all examples of what type of property?

katovenus [111]

Physical properties.

7 0

3 years ago

What does it mean to say B is representing the dominant gene

Degger [83]

Answer:

Dominant genes are always represented by a capital letter which in this case is the letter B whereas recessive genes will be represented by a lower case letter like b.

You only need one copy of a dominant gene or allele to inherit it. A dominant allele is always expressed even if only one copy is present.

But you need two copies of genes or alleles to inherit the recessive gene. There also can't be a dominant allele of the gene if you are to inherit this.

Allele - Different forms of a gene

8 0

3 years ago

How does the A Hreaction relate to the A He of molecules involved in a reaction?

igor_vitrenko [27]

Answer:

B. ΔHreaction = ΔH°f reactants- ΔH°f products

Explanation:

Using Hess's law, it is possible to sum ΔH of several related reactions to find ΔH of a particular reaction.

Having in mind Hess's law, ΔH°f is defined as the change in enthalpy during the formation of 1 mole of substance from its constituent elements (That is, pure elements, mono or diatomics, that have a ΔH° = 0).

For example, in ΔH°f of H₂O, the equation is:

H₂(g) + 1/2O₂(g) → H₂O(g)

The constituent elements with ΔH°f = 0 are H₂(g) and O₂(g).

Now, using Hess's law, you can sum the ΔH°f of substance in a reaction as, for example:

NaOH + HCl → H₂O + NaCl. ΔHr

The ΔH°f for each substance in the reaction is:

NaOH: Na + 1/2H₂ + 1/2O₂ → NaOH (1)

HCl: 1/2H₂ + 1/2Cl₂ → HCl (2)

H₂O: H₂ + 1/2O₂ → H₂O (3)

NaCl: Na + 1/2Cl₂ → NaCl (4)

The algebraic sum of (3) + (4) is -(ΔH°f reactants):

H₂ + 1/2O₂ + Na + 1/2Cl₂ → NaCl + H₂O ΔH°f reactants

This reaction - {(1)+(2)} ΔH°f products

NaOH + HCl → H₂O + NaCl.

ΔHr = ΔH°f reactants- ΔH°f products

In the example, we obtain this relationship that can be expanded for all reactions. Thus, right answer is:

<h3>B. ΔHreaction = ΔH°f reactants- ΔH°f products</h3>

8 0

3 years ago

13. According to Arrhenius definition which of the following is an acid *

VMariaS [17]

Answer: hcl

Explanation:

5 0

3 years ago

¿Qué elemento tiene el mismo número de órbitas que el Hidrógeno? ¿Por qué? ¿Tienen propiedades similares, por qué?

Aliun [14]

What element has the same number of orbits as Hydrogen? Why? Do they have similar properties, why?

Answer:

Helium

Explanation:

Helium has the same number of orbitals as hydrogen because they belong to the same period on the periodic table.

Periods are the horizontal arrangement of elements. Elements in the same period are known to have the same number of electronic shell or orbitals.

In period 1 where we have just Hydrogen and Helium, the number of orbitals is 1.

For properties of a specie, elements in the same group which are the vertical arrangement of elements have the same properties. Since both Hydrogen and helium are in different groups, their properties differ.

7 0

3 years ago