Can someone help me please!

Answer:

if you add a neutron to lithium-7 it becomes a compound nucleus of lithium-8

Here are two options use the one you need :)

Answer:

Energy can enter or exit an open system

Explanation:

D

Answer:

40km/h

Explanation:

v=20km/0.5h=40km/h.

Answer:

average speed=distance/time

speed=20/30

speed=2/3

Answer:

If the reactants in the chemical reactions are known, then the products can be predicted because the pattern of the chemical reactions is being followed. The pattern for a single replacement is A + BC --> AC + B. This is like the Hear It Pop Chemical Reaction which is also an example of the single replacement.

Explanation:

Answer:

a. increases

b. increases

c. decreases

Answer:

When the Sun's energy moves through space, it reaches Earth's atmosphere and finally the surface. This radiant solar energy warms the atmosphere and becomes heat energy. This heat energy is transferred throughout the planet's systems in three ways: by radiation, conduction, and convection.

Explanation:

Answer:

The sun radiates energy in all directions. Most of it dissipates into space, but the tiny fraction of the sun's energy that reaches Earth is enough to heat the planet and drive the global weather system by warming the atmosphere and oceans. The delicate balance between the amount of heat Earth receives from the sun and the heat that Earth radiates back into space makes it possible for the planet to sustain life.

Hopefully, this helps you out!

Answer:

The instantaneous speed at 2 seconds =

3 m/s

The average speed over the entire trip is

2 m/s

Explanation:

Answer above is wrong and doesn't state anything about the answer, so this is the correct answer hope this helped! :)

Answer:

1.) 3 m/s   2.) 2 m/s

Explanation:

I hope this helps!!

Answer: transcribing information to the dna sequence for use by the cell

Explanation:

Answer:

a

Explanation:

because

Answer:

A.) Compounds cannot be broken down into simpler substances by chemical means.

Explanation:

just took test on e2020 :)

1. heat gained : 1358.5 J

2. Cp metal = 0.121 J/g C

3/4 The metal = Lead

The law of conservation of energy can be applied to heat changes, i.e. the heat received/absorbed is the same as the heat released  

Q in = Q out  

Heat can be calculated using the formula:  

Q = mc∆T  

Q water(gained) = Q metal  (lost)

1. Heat of water gained

[tex]\tt Q=2500\times 4.18\times (25.13-25)=1358.5~J[/tex]

2. The specific heat capacity (C p) of the unknown metal :

[tex]\tt Cp=\dfrac{1358.5}{150\times (100-25.13)}=0.121~J/g^oC[/tex]

Answer:

A - dendrites

B - cell body

C - axon terminal

D - myelin sheath

E - nucleus

Hope that helps.

A-dendrite

B-cell body

C-axon terminal

D-axon

E-nucleus

Answer:

Dust and smoke.

Explanation:

Dust and smoke are two different particles present in the air. Dust and smoke are different from one another due to their origin. Smoke formed from burning of materials while dust refers to the soil particles lifted by the wind due to their light weight. Dust and smoke are similar to each other due to their small in size, infinite number means uncountable and light weight.

Air is a mixture of gases and consists of dust particles and water vapor. It consists of small to very large size of particles. Some of them include dust pollen, soot, and liquid droplets.

Hence they both differ.

Learn more about the two different particles found in the air.

brainly.in/question/35683807.

Answer:

11 atoms I think

Explanation:

Answer: 3

Explanation:

I took the test!!

Answer: [tex]2Cl^-(l)\rightarrow 2e^-+Cl_2(g)[/tex]

Explanation:

Electrolysis of a subastance is breaking it into its constituents by the action of electrical current.  

In the electrolysis of molten sodium chloride, sodium metal is produced at the cathode which is a negative electrode and chlorine gas produces as the anode which is a positive electrode.

[tex]2NaCl(l)\rightarrow 2Na^++2Cl^-[/tex]

At anode : [tex]2Cl^-(l)\rightarrow 2e^-+Cl_2(g)[/tex]

At cathode : [tex]2Na^+(l)+2e^-\rightarrow 2Na(l)[/tex]

2Cl- (l) → Cl2 (g) + 2e-

Answer:

А  There are two peroxide molecules on the reactant side.

The statement is correct because the left hand side is the reactant side. We can read the reaction as;

  2 molecules of hydrogen peroxide decomposed  to given 1 molecule of oxygen gas and 2 molecules of water .

D Mass must be conserved so there are an equal number of molecules in the reactants and products.

E Mass must be conserved so there are an equal number of atoms in the reactants and products.

Since the chemical equation is balanced, choices D and E are correct. The reaction will have equal number of molecules and atoms on both sides of the expression.

Explanation:

Answer:

No

Explanation:

The chemical reaction between magnesium metal and hydrochloric acid solution is not an acid - base reaction.

An acid - base reaction involves an acid and base to produce salt and water.

Answer:

SiF4 is not a polar covalent bond.

Explanation:

SiF4 is a nonpolar molecule because the fluorine's are arranged around the central silicon atom in a tetrahedral molecule with all of the regions of negative charge cancelling each other out.

Answer:

wave

Explanation:

'Wave' is a common term for a number of different ways in which energy is transferred: In electromagnetic waves, energy is transferred through vibrations of electric and magnetic fields.

i hope this helps and your welcom

Answer:

What is the question?

Explanation:

Answer: This law states that the volume and temperature of a gas have a direct relationship: As temperature increases, volume increases, when pressure is held constant. Heating a gas increases the kinetic energy of the particles, causing the gas to expand

Explanation:

According to this law, a gas's volume and temperature are directly correlated: When pressure is held constant, volume rises as temperature rises. The kinetic energy of the particles in a gas increases when it is heated, which causes the gas to expand.

According to Boyle's Law, when the temperature and mass are both constant, the volume of a given volume of gas sustained at a constant temperature varies inversely with the applied pressure.

The quantity of gas particles, the volume of the container, and the temperature of the gas all affect the pressure of a gas that is confined. The pressure will rise as the amount of gas particles in a container increases. The pressure will rise as a container's volume increases.

To learn more about rules apply to gases refer to:

https://brainly.com/question/25290815

#SPJ2

Answer:

positive ions are smaller than their parent atoms and negative ions are larger than their parent atoms.

Answer: c. peanut oil

Explanation:

There is a way to decrease the concentration of an ion here. The carbonate ion happens to be easy to decrease. All we have to do is add some acid (say HCl) to the container. The following sequence of reactions explains how this WO r ks.

As long as more acid is added, this process will continue until all the solid Zn CO3 has been dissolved

Answer:

HOPE IT HELPS...

Explanation:

When added to ice, salt first dissolves in the film of liquid water that is always present on the surface, thereby lowering its freezing point below the ices temperature. Ice in contact with salty water therefore melts, creating more liquid water, which dissolves more salt, thereby causing more ice to melt, and so on

Answer:

See detailed solution below

Explanation:

Now, let us solve each question step by step.

1) Given that;

N = amount of radioactive material at time t

No= amount of radioactive material originally present

t = time required for N amount of radioactive material to remain

t1/2= half life of the radioactive material

So,

N/No = (1/2)^t/t1/2

N/60 = (1/2)^22.8/3.8

N/60= (1/2)^6

N/60=1/64

64 N = 60

N = 60/64

N = 0.9 g

2) N/No = (1/2)^t/t1/2

N/8 = (1/2)^103.2/34.4

N/8 = (1/2)^3

N/8 = 1/8

8N = 8

N = 1 L

3)  N/No = (1/2)^t/t1/2

50/No =  (1/2)^18/6

50/No =  (1/2)^3

50/No = 1/8

No = 50 * 8

No = 400 micrograms

4)  N/No = (1/2)^t/t1/2

62.5/500 =  (1/2)^26/t1/2

0.125 = (1/2)^26/t1/2

Since 0.125 = 1/8

1/8 =  (1/2)^26/t1/2

(1/2)^3 = (1/2)^26/t1/2

Hence;

3 = 26/t1/2

t1/2 = 26/3

t1/2 = 8.7 hours