PLEASE HELP!!!<br> ILL MARK AS BRAINIEST AND GIVE YOU 30 POINTS!!!

I know the paper is blurry but can anyone explain any of the questions from 76-80?

Whitepunk [10]

Answer:try to make a good pic please I have ideas about the topic

3 0

3 years ago

Mercury is a liquid meteal but it is not hard? how can we say it is a metal

NNADVOKAT [17]

What's the problem ? Hardness is not the definition of a metal. You need to expand your thinking. EVERY element is solid, liquid, and gas, over different ranges of temperature ... including all of the metals. There are only TWO elements that are liquid AT ROOM TEMPERATURE, and mercury is one of them. But on a mild day at the south pole, mercury is solid too.

7 0

3 years ago

At a festival, spherical balloons with a radius of 280. Cm are to be inflated with hot air and released. The air at the festival

evablogger [386]

Answer:

8608.18 balloons

Explanation:

Hello! Let's solve this!

Data needed:

Enthalpy of propane formation: 103.85kJ / mol

Specific heat capacity of air: 1.009J · g ° C

Density of air at 100 ° C: 0.946kg / m3

Density of propane at 100 ° C: 1.440kg / m3

First we will calculate the propane heat (C3H8)

3000g * (1mol / 44g) * (103.85kJ / mol) * (1000J / 1kJ) = 7.08068 * 10 ^ 6 J

Then we can calculate the mass of the air with the heat formula

Q = mc delta T

m = Q / c delta T = (7.08068 * 10 ^ 6 J) / (1.009J / kg ° C * (100-25) ° C) =

m = 93566.96kg

We now calculate the volume of a balloon.

V = 4/3 * pi * r ^ 3 = 4/3 * 3.14 * 1.4m ^ 3 = 11.49m ^ 3

Now we calculate the mass of the balloon

mg = 0.946kg / m3 * 11.49m ^ 3 = 10.87kg

The amount of balloons is

93566.96kg / 10.87kg = 8608.18 balloons

5 0

3 years ago

Read 2 more answers

how many kilograms of water must evaporate from 8kg of a 25% salt solution to produce 40% salt solution?

Lena [83]

Answer: The kilograms of water must evaporate from 8kg of a 25% salt solution to produce 40% salt solution is 3 kg.

Explanation:

According to the ratio and proportion:

$C_1m_1=C_2m_2$

where,

$C_1$ = concentration of ist solution = 25%

$m_1$ = mass of ist solution = 8 kg

$C_2$ = concentration of second solution = 40%

$m_2$ = mass of second solution = ? kg

$25\times 8=40\times m_2$

$m_2=5kg$

Thus the final solution must have a mass of 5 kg , i.e (8-5)= 3 kg of mass must be evaporated.

Therefore, the mass that must be evaporated from 8kg of a 25% salt solution to produce 40% salt solution is 3 kg.

6 0

3 years ago

What is the name of an immune system response to a substance in food?

poizon [28]

Answer:

The adaptive (also called humoral or specific) immune system is typically only involved in immune responses to bacteria, bacterial toxins and virus antigens. It involves the production of antibodies (also called immunoglobulins) against a specific target. The target of an antibody is called an antigen.

3 0

3 years ago

PLEASE HELP!!! ILL MARK AS BRAINIEST AND GIVE YOU 30 POINTS!!!