Abeka 9th grade Science (Matter and Energy) Test 10

Au

gold

alkali metals

sent to a forensic laboratory for testing . The table below shows the initial testing results . A small piece of an unknown substance was found at a crime scene . The substance was Based on this data , in which category of elements does the unknown substance fit best ?

Na

sodium

periodic law

The law stating that elements show regular and repeating properties when arranged by increasing atomic number is the

chemistry

The organized study of the composition and interactions of matter is called ?

molecular mass

What term refers to the sum of the atomic masses of all the atoms in a molecule ?

half - life

What term refers to the time required for one half of a radioactive sample to decay into a new substance ?

dipole - dipole force

What type of intermolecular force is present between all polar molecules but not between nonpolar molecules ?

alpha decay

What type of nuclear decay occurs when an unstable atom ejects a clump of two protons and two neutrons ?

breeder reactor

What type of nuclear reactor produces more fuel than it consumes ?

gamma decay

What type of radioactive decay releases energy without changing the number of protons and neutrons ?

mole

What unit refers to 6.022 x 1023 particles of a substance ?

molality

What value relates the number of moles of solute per mass of the solvent ?

polar

When atoms with different electronegativities bond , what is the type of bond formed between the atoms ?

. 90 ° C water , stirred

Four beakers are filled with water . Two have water at 10 ° C , and the other two have water at 90 ° C . A sugar cube is added to each beaker . Two of the beakers ( one 10 ° C beaker and one 90 ° C beaker ) are stirred . In which beaker would you expect the sugar cube to dissolve most quickly ?

K

potassium

double bond

2. What type of bond occurs when two atoms share two pairs of electrons in a covalent bond ?

solution

A homogeneous mixture that consists of a solute dissolved in a solvent is a ( n ) ?

b .

A manufacturer needed to make a material with nonpolar molecules . Which of the following molecules meet this criterion ?

nonmetals

By physical properties , elements are divided into three groups : metals , semimetals , and ?

121.95 u

Calculate the formula mass of aluminum phosphate , AIPO , ( O : 16.00 u ; Al 26.98 u ; P : 30.97 u )

heterogeneous

If the molecules of a mixture are not completely mixed together , the substance is a ___?__ mixture

solute

In a solution , the substance that is dissolved is the

beta decay

In what type of radioactive decay is an electron emitted ?

ionic bonding

Magnesium is an alkaline earth metal , and chlorine is a halogen . The substance MgCl , most likely has

compound

What substance is composed of two or more elements bonded together ?

nucleus

Protons and neutrons are found in the

elements

What substances are composed of a single type of atom ?

The beakers on the dresser were at a cooler temperature .

Sheldon wanted to know the rate at which granulated fertilizer dissolves in rainwater . He was completely dissolved in the beakers on the windowsill , but a solid substance remained five beakers on his windowsill and five beakers on his poured rainwater into ten beakers and added 15 g of fertilizer to each beaker . He placed dresser . After four days , the fertilizer in the beakers on the dresser . What is the most likely cause of this observation ?

fusion

The process of combining two nuclei to form a heavier nucleus is

diffusion

The process of mixing molecules of one substance with those of another substance by random molecular motion is called ? .

critical mass

What term refers to the minimum amount of fissionable material required for a chain reaction to occur

isotopes

What are atoms of the same element that have different mass numbers ?

valence electrons

What are the electrons located in the outermost shell of any atom called ?

calcium

What element has the symbol Ca ?

Pauli exclusion principle

What idea states that no two electrons in an atom can have the same set of four quantum numbers ?

quantum theory

What idea states that tiny particles do not absorb or release energy in a smooth flow but in specific amounts ?

London force

What intermolecular force occurs between all molecules ?

colloid

What is a mixture containing tiny suspended clumps of particles called ?

osmosiss

What is one - way diffusion through a semipermeable membrane ?

sulfur tetrachloride

What is the chemical name for the compound SCI ?

uranium hexafluoride

What is the chemical name for the covalent compound that contains one uranium atom and six fluorine atoms ?

mixture

What is the general term for a physical combination of pure substances ?

period

What is the general term for a row of elements in the periodic table ?

26

What is the mass number of the element 25Mg ?

4.4 mol / kg

What is the molality of a solution containing 15 mol of sucrose ( C₁₂H₂O ) dissolved in 3.4 kg of water ?

27.67 u

What is the molecular mass of B , H ? ( B : 10.81 u ; H : 1.008 u )

mercury

What is the only metal that is liquid at room temperature ?

hydrogen bond

What is the strongest intermolecular force ?

electronegativity

What property describes how strongly atoms of an element pull on electrons in a chemical bond ?

. : C :

Which of the following elements would complete the Lewis structure shown below based on the octet rule ? H : N : H

Hydrogen must be bonded to nitrogen , oxygen , or fluorine

Which of the following factors must be present for hydrogen bonding to occur ?

. HF ( polar )

Which of the following has the strongest intermolecular forces ?

C.

Which of the following images illustrates the Bohr model of the atom ?

cation

Which of the following is an atom that has a positive electric charge because of losing electrons ?

CH₂

Which of the following is an example of an empirical formula ?

All atoms are made of subatomic particles

Which of the following is not a principle of the atomic theory ?

table salt

Which of the following is not a suspension ?

octa

Which of the following prefixes is used when naming fluoride in the covalent molecule SeF₂ ?

O

oxygen

Essay : For the following substances , identify what types of intermolecular forces are present : zinc chloride ( ionic crystal ) , silicon tetrafluoride ( a nonpolar covalent molecule ) , and hydrogen fluoride ( a polar covalent molecule ) . Additionally , predict the substances ' state of matter at room temperature .

• Zinc chloride has no intermolecular forces because it is ionic . ( lonic bonds do exhibit electrostatic force . ) Such bonds require large amounts of heat to change from a solid to liquid . Zinc chloride is a solid at room temperature . • The only force silicon tetrachloride because there is not a strong intermolecular force between the atoms of nonpolar exhibits is London force . It is likely a gas at room temperature covalent molecules to overcome . . All three intermolecular forces ( London force , dipole - dipole force , and hydrogen bonds ) are present could be a liquid or solid depending on the actual room molecules . A hydrogen bond is present because in hydrogen in fluoride . London force and dipole - dipole force are present in all polar covalent temperature ( melting point of HF is 19.5 ° C ) . hydrogen is bonded to fluorine . Hydrogen fluoride