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
WARRIOR [948]
3 years ago
10

What is thought to have caused the mass extinction at the end of the Cretaceous Period? A) global warming Eliminate B) an astero

id hitting Earth in Mexico C) extensive volcanic activity world-wide D) the start of glaciation and climatic changes
Biology
2 answers:
GalinKa [24]3 years ago
5 0

The answer is B. Geology has shown a thin layer of iridium (a rare mineral on earth but found on asteroids and meteors) in the rock layers between the Cretaceous and Paleogene periods. Below this layer are numerous fossils of  pterosaurs and dinosaurs, but above the layer are drastically few. The aftermath of asteroid impact is believed to have smothered most vegetation from earth which dinosaurs depended on as a source of food.  






kifflom [539]3 years ago
5 0

Answer:

B

Explanation:

You might be interested in
¿Qué se puede agregar a un átomo para hacer que un electrón sin valencia en el átomo se convierta temporalmente en un electrón d
NNADVOKAT [17]

Energía.

Explicación:

Generalmente, los electrones giran continuamente en las capas de los átomos. Si estos electrones se encuentran en las capas más externas de un átomo, se denominan electrones de valencia.

Son necesarios para las reacciones químicas de un átomo en particular con otro, a través de sus pérdidas o compartidas.

En los átomos sin valencia, sus capas más externas no tienen electrones en sus capas más externas, tales átomos son estables.

Sin embargo, si se suministra cierta cantidad de energía a dicho átomo, el electrón gana energía y, por lo tanto, se excita.

Por lo tanto, se mueven de niveles de energía más bajos a niveles de energía más altos, y hacen que el átomo sin valencia se convierta en valencia temporalmente, a medida que se mueven hacia la capa más externa.

Answer:

Energy.

Explanation:

Generally, electrons revolves continuously in the shells of  atoms.if these electrons are located in the outer most shells of an atom,they are refereed to as the Valence electrons.

They are needed for chemical reactions of a particular atom with another,through their loses or sharing.

In Non -valence atoms their outermost shells do not have electrons at their outermost shells,such atoms are stable.

However, if  certain quantity of energy is supplied  to  such atom, the electron  gains energy and therefore becomes excited.

They therefore move from lower energy levels to higher energy levels,and makes the non- valence atom becomes valence temporarily, as they move into the outermost shell.

5 0
3 years ago
This is the force of attraction between an object and the earth due to gravity.
weeeeeb [17]

Answer:

Gravitational force

Explanation:

Gravitational force is the force that attracts an object down to the earth. It’s also the reason why we don’t float on this planet. This force is also why anything that isn’t thrown up must come down.

In space and other planets with little or no gravitational force ,organisms float over there which makes its inhabitation by organisms very difficult.

4 0
3 years ago
Read 2 more answers
10 examples of unwanted friction that can be lowered
olga55 [171]

Answer:

List three ways of reducing friction. 1.Polishing the rough surface. 2.Providing all bearings or wheels between the moving parts of a machine or vehicles reduce friction and 3.allow smooth movement as rolling friction is less than sliding friction.

8 0
3 years ago
What makes an allele dominant recessive or codominant
kati45 [8]
Dominant refers to the relationship between two versions of a gene. Individuals receive two versions of each gene, known as alleles, from each parent. If the alleles of a gene are different, one allele will be expressed; it is the dominant gene. The effect of the other allele, called recessive, is masked.
7 0
3 years ago
The Hubble constant measures distance in?
PIT_PIT [208]

GIVE ME BRAINLIEST PLS LOL    

The value of the Hubble constant is estimated by measuring the redshift of distant galaxies and then determining the distances to the same galaxies (by some other method than Hubble's law). Uncertainties in the physical assumptions used to determine these distances have caused varying estimates of the Hubble constant.

4 0
3 years ago
Other questions:
  • Which of these is a type of mass movement that is likely to happen after a large amount of rain?
    14·2 answers
  • Select the correct answer. A normal appearing couple is found to be heterozygous recessive for albinism. Both have the genotype
    10·1 answer
  • What is the plate boundary at which one plate is pushed beneath another called?
    11·1 answer
  • "This leaf is 4 inches long"<br> What kind of observation is this?
    8·2 answers
  • U
    10·1 answer
  • The domestic cat genome contains 2.9×109 base pairs. The length of linker DNA in mammals is 50 base pairs. Approximately how man
    11·1 answer
  • The ribosomes produce proteins which.are carried through the cell by the
    13·1 answer
  • Checking for contents of the intestinal tract would be done during which phase of the autopsy?
    9·2 answers
  • Somatostatin hücrelerden hangisinden salgılanır
    15·2 answers
  • URGENT!! list 16 things in your house or yard that contain oxygen
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!