How will you know if a chemical change has occurred when the reactants are combined? Use evidence and scientific reasoning to support your answer.

Answer:

I would know if a chemical change is occurred if a new material is formed which doesn't share any characteristics of the reactants example if we expose iron to water and air a new material is formed (rust) which doesn't share any characteristics of iron,water or air.

What is the purpose of DNA?

Substance X is extremely acidic. Substance Y is extremely basic. What would be formed if substance X and Y were mixed together?


A basic substance

An atomic bomb

A salt and water(H20)

An acidic substance

Two brothers are participating in a race. The older brother's average speed is 6 miles per hour and he finishes the race in 1 hour and 20 minutes. If the younger brother's average speed is 4 miles per hour, how long will it take him to complete the race?

A.) 45 min

B.) 2 Hours

C.) 4 Hours

D.) 30 min

Another science question because i dont know it so i need more help

(I'LL GIVE BRAINLIEST TO WHOEVER ANSWERS FIRST!)How do the properties of magnets allow them to be useful to society?

PLS HELP MY TEACHER IS MAKING ME DO THIS TODAY IF U ANSWER CORRECTLY I WILL HIVE BRAINLY
Glyptodon is a giant, armadillo-like animal that once lived on Earth and weighed over 2000 kilograms (kg) and lived almost exclusively in warm, wet coastal regions. In many ways it resembled the 4 kg armadillo that lives today. From the information given, what is the probable reason Glyptodon is not alive today?

A. Predators hunted the animal for food to the point of extinction.
B.The animal could not adapt to environmental changes.
C.The animal ate too much food.
D. The Glyptodon had genetic variation.

Which statement refers to convection?


Sunlight travels through space without the aid of fluids or solids.


Land and ocean absorb and re-emit heat from the sun.


Some of this energy is reflected off Earth's atmosphere.


Warm air rises and takes heat with it; eventually it cools and sinks.

Which energy source can be used as an energy source that may otherwise be thrown away?
solar
wind
water
biomass
or geothermal?

Brass is an alloy of copper and zinc. Bronze is an alloy of copper and tin. Alloys are commonly used in manufactured items because the properties of these metal mixtures are often superior to a pure metal.

1. What direction does water move if a cell is placed in salt water?

2. What direction does water move if a cell (slightly salty) is placed in pure distilled water?

3. What direction does water move if the concentration of salt is the same inside and outside of the cell?

4. What organelle of the cell controls movement in and out of the cell?​

Bicarbonate is a solution present in human blood. Bicarbonate helps to maintain our bodies pH and resists pH change. Bicarbonate is an example of a(n) ______________________.


Indicator

Buffer

Acid

Some hormones enter cells via

Please help me out with this question if you help me I will give you the brain thing and extra points. 8/9 image below.

Please help me out with this question if you help me I will give you the brain thing and extra points. 2/9 image below.

what is matter and what are some thing that are living and nonliving

Which factor is most important in determining climate?
longitude


latitude


hours of daylight


time zone

To find S, the number of shared

electrons, recall that

S = N-A

What is S for silicon

tetrachloride, SiCl4?

The movement of tectonic plates in two locations is described below:

Location A: Tectonic plates push together
Location B: Tectonic plates slide past each other

Which statement is most likely true?

Earthquakes may occur in both locations.
Volcanic eruptions may occur in both locations.
Earthquakes may occur in location A but not in location B.
Volcanic eruptions may occur in location B but not in location A.

Which of the gases below is found at high levels near the surface of the ocean due to plant photosynthesis?
A.
nitrogen
B.
neon
C.
oxygen
D.
carbon dioxide

how does the respiratory system aid the digestive system


a. the lungs take in oxygen to aid in food digestion

b.the lungs take in carbon dioxide to aid in food digestion

c. the expand the diaphragm, which helps to push the stomach during digestion

d. the lungs contract the diaphragm, which helps to push the stomach during digestion

PLEASE HELP ASAP ! :)

Question 1: A measure of the amount of matter in an object


Question 2: the force or speed with which something moves


1.momentum
2.collision
3.exert
4.mass
5.velocity

After you set up a fish tank, you are sure to see algae growing in it. There is plenty of light, fertilizer in the form of fish droppings, and plants or glass for algae to cling to. You may see green strings of algae in the water or green spots growing on the glass. Your whole aquarium can turn green if you don’t stop the algae. To prevent the problem, you can add algae-eating fish or microorganisms to the water. Covering the aquarium for a few days will also kill algae, which need photosynthesis to survive.

Multi-celled algae grow into larger organisms through cell division. For one-celled algae, the purpose of cell division is

How do you put this in your own words-

This amount depends on the latitude of the area. Latitude is the angular distance in degrees north and south from the equator. Different latitudes receive different amounts of solar energy.

I need help! :)
-"When a sedimentary rock changes shape under heat and pressure,but does not melt completely,it becomes which of the following?

A:Igneous
B:Magma
C:Metamorphic
D:Volcanic ​

Brass is stronger than steel
True or False

Which of the following options best explains how less chlorophyll would affect the process of photosynthesis in plants?

Group of answer choices

It would limit the amound of light absorbed by the plant and decrease the amount of food the plant is able to produce for itself.

It would increase the rate of photosynthesis becasue of the increased production of food.

It would limit the amount of water plants are able to take in, resulting in a slower rate of photosynthesis.

It would increase the production of oxygen becasue the plant would need to work hard to feed themselves.

Draw a molecule and yeah that's basically it

cells are made up mainly of proteins and carbohydrates how do these molecules function in the cell membrane
pls i need it!!

a clear liquid is poured into a beaker containing another clear liquid. A cloudy yellow substance forms, as if out of nowhere, but the rest of the liquid remains clear. what happened?

instruction
ACTIVO
Describing the Energy on a Slide
CE
A
Each sentence describes potential and kinetic energy
at various locations on a slide. Complete each
statement by selecting the position of the object on the
slide.
An object at position vhas all kinetic energy
An object at position has all potential energy
An object at position has about half potential energy
and half kinetic energy,
B
С
Intro
Done